Centennial Celebration
Historic Timeline
Assembled by
the Arizona Section
of the American Society of Civil Engineers
Celebrating 100 years
1925-2025
of the Arizona Section
Skip Ahead 
The Hohokam people lived in Mesa for nearly 1,500 years. They first appeared around 1 BC, initially growing beans, squash, corn, and cotton to serve a small population of less than one thousand people. 
Around 600 AD their population was growing rapidly so irrigation canals began to be built. To meet their living needs, the Hohokam designed the largest and most complex irrigation system in the Americas. Their digging ability is considered a genius in hydraulic engineering. Their efforts to build irrigation canals ultimately became the foundation of Arizona’s economy and urban development. Companies emerged, revitalizing the irrigation system. The Hohokam Canal System is recognized as an ASCE National Historic Civil Works.
Since 1871, building on the legacy of the Hohokam people, nine major canals have emerged across the greater Salt River Valley. In 1902 the National Reclamation Act was passed into law, providing for the government to reclaim arid lands in the west with irrigation projects. In 1903, Valley settlers formed the Salt River Valley Water Users’ Association (SRVWUA), which is still part of SRP today. In 1917 the operation of the canal system was turned over to the SRVWUA, which still operates the canals for the federal government today.
The oldest continuously used canal in SRP’s system
In 1871 Yuma incorporated and became the county seat of Yuma County. The Territorial Prison was authorized by the legislature in 1875. Ground was broken on April 28, 1876, and some of the prisoners were pressed into service to build their cells. The first seven inmates moved into the facility on July 1, 1876. The prison continued in operation until 1909 (33 years) when, due to overcrowding, all inmates were moved to a new facility in Florence.
The oldest remaining pioneer canal on the north side of the Salt River. The original heading of the canal was plagued by washouts, so the Old Crosscut Canal (1889 and 1912) was built to provide a more reliable water supply from the Arizona Canal. The New Crosscut Canal was constructed in 1912, extending from the Arizona Canal near 64th Street to the Crosscut Hydroelectric Generating Station south of Washington Street, thus providing electric power generation while still allowing for the delivery of irrigation water.
The Southern Pacific Railroad, building the nation’s second transcontinental rail line eastward from California, reached Tucson on March 20, 1880. It was the occasion for one of the greatest celebrations in the history of the city and foretold the coming of a new era of fast, reliable and inexpensive transportation, bringing growth, development and prosperity. The original station, built in 1880, was a large wooden structure with offices, freight and passenger accommodations. It was replaced by the present depot, built on the same site in 1907.
The northernmost of the 131-mile water distribution system. More than 38 miles long, it is the longest in the SRP’s system. Beginning at the Granite Reef Diversion Dam northeast of Mesa, it flows west across the Valley before ending at New River near Arrowhead Towne Center.
Founded in 1884, APS is Arizona’s largest and longest serving electric utility, providing power for nearly 1.4 million customers in 11 of the state’s 15 counties. APS is owned by Pinnacle West Corporation, an American utility holding company. As an energy utility, it generates, procures, transmits, and distributes electricity to central and southern Arizona. Its balanced and diverse energy portfolio includes carbon-free nuclear energy from Palo Verde Generating Station, the largest producer of clean energy in the US.
The University of Arizona was established in 1885, and 27 years later Arizona became a state. The public land-grant research university was founded by the Thirteenth Territorial Legislature as the first university in the Arizona Territory. Classes met for the first time with 32 students in Old Main, the first building constructed on the 40-acre campus. In 1889 the Arizona Board of Regents expanded the scope of UofA to include the School of Agriculture. Later in and around 1891, Civil Engineering was one of two professional degrees available in the School of Agriculture. Degrees in Civil Engineering were not conferred until 1904. The university is recognized as a research institution, having received more NASA grants for space exploration than any other university nationally.
On February 8, 1886, the Territorial Normal School opened its doors to 33 students in a four-classroom building in Tempe. Now known as Arizona State University, it was created by the Thirteenth Territorial Legislature to train teachers and teach agriculture and mechanical arts. Arizona State Teachers College (ASTC) offered its first graduate degree, master’s in education, in 1937. In 1945 its name changed to Arizona State College and earned authorization to grant bachelor’s degrees. In 1958 a measure placed on the ballot by citizen initiative, Prop 200, recognized the longstanding efforts to advance the fast-growing college and its name was changed again to ASU. Also in 1958, the School of Engineering was started. In 2002 Michael Crow unveiled his vision for a New American University. Since then, ASU has established more than a dozen new transdisciplinary schools and launched large-scale research and initiatives and programs in the humanities and social sciences.
In 1889 John Gardner started the first Phoenix Waterworks at what is now Verde Park in the Garfield District near 9th Street and VanBuren Street. Known as the Phoenix Water Works Company, it was the first privately owned water company. In the early days of Phoenix, water was delivered by a redwood pipeline from the Verde River over 30 miles away and distributed by a canal across the city. The 38-inch diameter redwood pipeline was built of staves bound with steel much like a barrel, with sections placed end-to-end. In December 1903 the voters approved the sale of bonds to create a municipal water system. Once the legal red tape was removed Phoenix purchased the Phoenix Water Company on July 1, 1907.
The most significant dam failure experienced in Arizona occurred in Walnut Grove on February 22, 1890. The Walnut Grove Dam was constructed approximately 20 miles northeast of Wickenburg on the Hassayampa River. Gold had been discovered in the area and a New York investor wanted a dam built to supply water for hydraulic mining. Work began on the rockfill dam in February 1886. The dam failed due to overtopping and the ensuing flood destroyed homes, mines, farms, and caused over 100 deaths.
TEP is an electric utility company serving southern Arizona. It is a subsidiary of Fortis, which announced its acquisition of its parent company UNS Energy in 2013. In 1892 a group came together to form the Tucson Electric Light & Power Company. Four years later the company purchased the Tucson Gas Company and by 1901 it was known as Tucson Gas, Electric Light and Power Co. The renamed Tucson Gas & Electric was sold in a public offering. In 1979 the gas operations were sold to Southwest Gas and the company was renamed Tucson Electric Power. In 1998 TEP created a new holding company, UniSource Energy, of which TEP became a subsidiary.
Flagstaff became incorporated as a town in 1894. The city grew rapidly, primarily due to its location along the east-west transcontinental railway , with about 80 to 100 trains traveling through the city every day. The railroad, which became the Sante Fe Railroad, largely controlled Flagstaff, being its main source of industry and transport, until Route 66 was completed in 1926, with a section through Flagstaff.
Established in 1894, is an astronomical observatory located in Flagstaff. It is among the oldest observatories in the United States and was designated a National Historic Landmark in 1965. It was at the Lowell Observatory that the dwarf planet Pluto was discovered in 1930 by Clyde Tombaugh. The main facility, located on Mars Hill, houses the original 24-inch Clark Refracting Telescope. The observatory currently operates four research telescopes at its Anderson Mesa dark sky site, located 12 miles southeast of Flagstaff, including the 72-inch Perkins Telescope and the 42-inch John S. Hall Telescope. On the peak of Happy Jack, Lowell Observatory built the 169-inch Lowell Discovery Telescope.
The most significant dam failure experienced in Arizona occurred in Walnut Grove on February 22, 1890. The Walnut Grove Dam was constructed approximately 20 miles northeast of Wickenburg on the Hassayampa River. Gold had been discovered in the area and a New York investor wanted a dam built to supply water for hydraulic mining. Work began on the rockfill dam in February 1886. The dam failed due to overtopping and the ensuing flood destroyed homes, mines, farms, and caused over 100 deaths.
1900
NAU opened its doors as Northern Arizona Normal School on September 11, 1899, with one professor and twenty-three students in one building, now known as Old Main. Four women made up the first graduating class of 1901, receiving lifetime teaching certificates for the Arizona Territory. In 1925 the school was renamed Northern Arizona State Teachers College (NASTC), a four-year institution with the power to grant the Bachelor of Education degree. On July 1,1929, NASTC became Arizona State Teachers College (ASTC) at Flagstaff. With the end of the world war in 1945, the name of the school changed again, becoming Arizona State College at Flagstaff, now offering several other degrees besides teaching. The Arizona Board of Regents recommended the institution become Northern Arizona University effective May 1, 1966.
The State Capitol building was dedicated on Feb 25, 1901, built at a cost of $130,000.
The Santa Fe and Grand Canyon Railroad was built to extract copper ore from Anita Camp, 8 miles south of the Grand Canyon. Although the mine played out about the time the railroad reached Anita, it was sold to AT&SF Railway in 1901, who built the short extension to the Grand Canyon. 
The Grand Canyon Railway brought visitors to the historic El Tovar Hotel until 1968 when it was shut down due to the popularity of automobiles. But the 65 miles of track was reopened to passengers in 1989, and was recognized as an ASCE State Historic Civil Engineering Landmark in 2000.
USBR was established in 1902.
SR88, also known as the Apache Trail, is one of the original ten state highways designated by the Arizona State Highway Department in September 1927.
The original route was started in 1904 as a wagon road to aid in the construction of the Theodore Roosevelt Dam. It was built and maintained in sections. State transportation workers graded the single-lane, 12 foot-wide road for safety and drainage for the first time in 1915. In 1936, the road was widened to 16 feet and gravel applied. In 1949 and 1950, a bituminous surface treatment was applied to the southernmost sections which were widened to 22 feet between Apache Junction and the Fish Creek Bridge to accommodate motor vehicles. SR88 extends from Apache Junction to Arizona 188 at Roosevelt Lake.
Laguna Diversion Dam is a rock-filled diversion dam on the lower Colorado River, located 13 miles northeast of Yuma. Constructed between 1903 and 1905, it was the first dam built on the Colorado River and subsequently ended boat travel to the north. After passage of the Reclamation Act by the US Congress in 1902, the US Bureau of Reclamation began constructing the dam under the Yuma Project. The dam’s design and size made it a peculiar structure for its time. The dam, a weir, was merely 43 feet high, almost two-thirds of which were built below the riverbed. After the creation of the Imperial Dam 5 miles upstream, the Laguna Diversion Dam was no longer needed and its California diversion outlets were closed in 1948. Since then, the dam serves to regulate the outflows of the Imperial Dam.
The 10-mile long South Canal (1908) serves the purpose of taking water from the Salt River at the Granite Reef Diversion Dam to all the other canals on the south side of the Salt River. The three most significant features along the canal are the Val Vista Water Treatment Plant, the Hennessy Wasteway and the South Consolidated Hydroelectric Plant.
doesn’t store water or generate power, but it does have a critical role in delivering water to the Salt River Valley. The dam diverts water released from storage dams on the Salt and Verde rivers into the Arizona and South canals. The Arizona Dam, precursor to Granite Reef, diverted water for canals on the north side of the Salt River in the early 1900s. A flood washed out the structure in April 1905. This led the government to buy the northside canal system and construct the Granite Reef Diversion Dam. Designed as a single point of diversion for all the northside and southside canals, the concrete dam was authorized in June 1906. Construction of the 29-foot-high, 1,000-foot-long dam was completed in May 1908.
In 1909 the Office of Territorial Engineer was created. It placed all territorial road and bridge construction and maintenance under the supervision of the Territorial Engineer.
(1873-1949) was appointed the first Territorial Engineer on April 1, 1909. He laid out the routes for many of today’s highways, including Interstates 8 and 10. He supervised the design and construction of the Ash Avenue bridge in Tempe spanning the Salt River, which today is listed on the National Register of Historic Places. He constructed dams for both water conservation and flood control, including the construction of Cave Creek Dam in 1921. He was responsible for selecting the preliminary route for the 190-mile Central Arizona Project in 1940, beginning at the Parker Dam near Lake Havasu and extending to the Granite Reef Diversion Dam near Mesa. He served as president of the Arizona Section of ASCE in 1929.
West of Lindsay Road, the South Canal splits and becomes the Eastern Canal (1909) and the Consolidated Canal (1891). Today the Eastern Canal is the site of the town of Gilbert’s water filtration plant. The Consolidated Canal is the longest canal in Mesa, roughly 18 miles long. It delivers water to the Chandler Water Filtration Plant, located south of Pecos Road.
The first Tempe Canal headed in the Salt River near what is now Mesa Drive in Mesa. It flowed along 8th Street to downtown Tempe and on to the west. The Western Canal (1911-1913) was built to serve SRP lands in south Phoenix after the US government tried but failed to purchase the Wormser Branch of the Tempe Canal. From the Tempe Canal, the Western Canal heads west then turns and curves around to the northwest along the foothills of South Mountain. Roughly at the Maricopa Freeway, the canal continues its western route, then dips to the southwest near 7th Avenue.
The first sewer system in Phoenix was a private utility, completed in 1892. In 1911 the city of Phoenix purchased a private sewer system and began wastewater operations. Although there were individual septic tanks and cesspools in use to dispose of wastewater, the early franchise disposed of raw wastewater at a sewage farm at 15th Ave near the Salt River.
The city built a large facility there in 1913, and in 1915 extended the system with a series of settling tanks at 19th Ave and the river. An actual industrialized facility to treat wastewater didn’t exist until 1932, when the 23rd Avenue Wastewater Treatment Plant was completed and began operation.
was originally built from 1903 to 1911 using stone cut from the canyon walls and set with cement manufactured on-site in the Tonto Basin. Flooding proved challenging, however, and disrupted work several times during construction. It provided flood control, irrigation and hydroelectric power to the Salt River Valley. The dam was dedicated by Theodore Roosevelt on May 18, 1911. It was designated as an ASCE National Historic Civil Engineering Landmark from 1963 to 1989, but with renovation in the 1990s it no longer has the integrity of the original design.
Louis Clarence Hill (1865-1938) was the designer and supervisory engineer for the construction of Theodore Roosevelt Dam. He was placed in charge of the Roosevelt project in the spring of 1904, remaining until March 1911. His outstanding work for the Federal Government was done on Boulder Dam (now Hoover Dam) on the Colorado River; Coolidge on the Gila River; Elephant Buttes in New Mexico; and Bonneville Dam on the Columbia River.
He served as president of ASCE in 1937.
The Southern Pacific Railroad, building the nation’s second transcontinental rail line eastward from California, reached Tucson on March 20, 1880. It was the occasion for one of the greatest celebrations in the history of the city and foretold the coming of a new era of fast, reliable and inexpensive transportation, bringing growth, development and prosperity. The original station, built in 1880, was a large wooden structure with offices, freight and passenger accommodations. It was replaced by the present depot, built on the same site in 1907.
Arizona became the 48th state of the United States on Feb 14, 1912.
In 1912 the Office of the Territorial Engineer was replaced with the Office of the State Engineer, which was the predecessor to the Arizona Department of Transportation (ADOT).
(1870-1926) succeeded James Bell Girand as State Engineer on March 14, 1912. He served until 1915. His report to the governor in 1914 stated that Arizona’s official road system consisted of two roads consisting of 251 miles. He was directed by Arizona’s first road law to establish a state highway system. A monument in his honor can be found on US 80 (SR 83) where it intersects I-10.
is located about 12 miles southeast of Winslow. It is a steel Warren Pony truss bridge over Chevelon Creek, built on the first permanent road connecting Holbrook and Winslow. It was constructed in 1913. The bridge is 90 feet above the water level of the creek, spanning abutments 102 feet apart. The bridge has been listed on the National Register of Historic Places since 1983, being a rare design in Arizona, part of an early transnational roadway and being in nearly original condition.
a civil engineer, was selected as the first City Manager for the City of Phoenix in 1914.
(1881-1961) became the Dean of the UofA College of Mines and Engineering as well as head of the local office of the U.S. Bureau of Mines in 1915. In 1921 he assisted in the formation of the State Board of Technical Registration. He served on the board from June 23, 1921, until July 16, 1951. He was responsible for the growth and development of engineering at UofA. He held the State of Arizona Professional Registration #1 as a Mining Engineer and Geologist.
On May 22, 1915, the Ocean-to-Ocean Bridge opened over the Colorado River at Yuma, serving as the only link for auto travel from the east coast to the west coast. It was the first highway crossing of the lower Colorado and is the earliest example of a through truss bridge in Arizona. Originally the bridge carried the transcontinental Ocean-to-Ocean Highway, and later its successor, US 80, until a new bridge was built to the east in 1956. Closed to vehicular traffic between 1988 and 2001, but after a major rehabilitation it was reopened in 2002. The bridge became part of Historic US 80 in 2018.
The Federal Aid Highway Act of 1916, called the Bankhead-Shackleford Act or Good Roads Act, which was promoted by the national Good Roads and bridges movement, required state highway departments to be formed and be run by civil engineering professionals to carry out the federal aid projects. This act helped create a demand for civil engineers, especially in Arizona.
Arizona adopted its State flag on February 27, 1917.
In 1919 Tucson opened the first municipally owned airport in the US. In 1928 commercial flights began with Standard Airlines (later American Airlines); regular airmail service began in 1928. Tucson International Airport is a civil-military airport owned by the City of Tucson 8 miles south of downtown Tucson. In 1948, the Tucson Airport Authority was created as a non-profit corporation to operate the airport and oversee policy decisions. Tucson International Airport hosts Morris Air National Guard Base, a 92-acre complex on the northwest corner of the airport that is home to the 162nd Wing of the Arizona Air National Guard. Military use of Tucson Airport began in 1956.
established in 1921.
is an open spandrel arch bridge which crosses Cienega Creek and the Union Pacific Railroad near Vail, Arizona. Originally constructed in 1921, the bridge was part of US Route 80, a major transcontinental highway, from 1926 to 1956. Being the oldest bridge of its kind in Arizona, the Cienega Bridge is listed on the National Register of Historic Places. The bridge also holds the title of being the longest open-spandrel concrete arch within the state. Currently the bridge carries Marsh Station Road, which is part of Historic US Route 80 as of 2018.
In 1922 Frank Caleb Kelton (1881-1942) became head of Civil Engineering at the University of Arizona, a position he held until his death in 1942. Mr. Kelton was the UofA’s first Bachelor of Science in Civil Engineering recipient in 1904. He had been teaching at UofA since 1907. Mr. Kelton was President of the ASCE Arizona Section in 1932.
A 1922 agreement among seven States in the watershed of the Colorado River governing the allocation of water rights to the river’s water among the parties.
is a reinforced-concrete barrel-arch structure located near Cave Creek. Built in 1923 by John Samuel Eastwood, it was the primary dam preventing flooding in North Phoenix from 1923 to 1979. In the early days of Phoenix, seasonal flooding was considered to be a barrier to growth. There were particularly devastating floods in 1905 and 1921 in Cave Creek Wash. 
The dam was replaced by the zoned earthen embankment, Cave Buttes Dam, located a little bit downstream in Cave Creek Wash. The original dam no longer provides flood protection, but it was left in place for historic preservation.
1925
On April 20, 1925, the Arizona Section of the American Society of Civil Engineers (ASCE) was established.
In 1925 transportation officials changed the jumble of named highways to a consistent numbering system, adopting the familiar US Highway shield. With this change, the southern route that had been the Dixie Overland/Lee/Bankhead/Ocean to Ocean /etc. Highway was dubbed US 80, the Mother of Arizona highways. A 1927 printed log of the nation’s highways listed US 80 as being 2,726 miles long, with the Arizona portion following a circuitous route that passed through Douglas, Bisbee, Tombstone, Benson, Tucson, Mesa, Phoenix, Buckeye, Gila Bend and Yuma. Both it and US 66 were completely paved or surfaced with oil in Arizona by 1939. With the advent of the interstate highway system, much of US 80 was renamed I-8 or I-10, or was replaced by SR 77, SR 79, US 60 and SR 85.
George E. P. Smith (1873-1975) was a graduate of the University of Vermont and accepted a position with the UofA in 1900 to teach physics and civil engineering. An irrigation engineer, he was a proponent of the importation of water from the Colorado River from the Diamond Creek Dam site.
He was an authority on irrigation and a pioneer in the development of underground and surface waters in the state of Arizona. He taught at the UofA until his retirement in 1955, but continued his active interest in the field of water resources development. In February 1925, he invited 28 eligible engineers to meet with him in the Adams Hotel in Phoenix to discuss establishment of an Arizona Section. Mr. Smith was selected as the first president of the ASCE Arizona Section. He served on the National Committee of ASCE while at the UofA.
In 1925, the Yuma Chamber of Commerce sought to secure an airport for Yuma. After two years of negotiations, 40 acres of land was secured from the federal government and Yuma International Airport was created. In 1941 the airport became Yuma Army Air Field, and the field was used for advanced pilot and gunnery training. In 1946 Yuma Army Air Field was scaled back and declared a surplus. The civilian portion of the field was returned to Yuma County, who again referred to it as Fly Field. In 1959, control of the base was given to the US Marine Corps, and in 2007 a resolution was passed declaring that Yuma International Airport was an aviation partner with Marine Corps Air Station Yuma.
In 1926 the University of Arizona formed the ASCE student chapter.
also known as the Will Rogers Highway, was a major US numbered highway in Arizona from 1926 to 1985. The highway ran from west to east, covering 385 miles. Starting in Needles, California, it extends through Kingman and Seligman to the New Mexico state line. With the passage of the Federal Aid Highway Act of 1956, bringing into existence the Interstate and Defense Highway System, several highways were chosen to become corridors for new interstates, including US 66 which was to be replaced by I-40. By 1967 over 115 miles of I-40 had been constructed or rebuilt from US 66, with another 82 miles underway. Controversy came with construction of I-40, particularly opposition to freeway bypasses around towns along the route.
Three dams and reservoirs were constructed on the Salt River for the Salt River Valley Water User’s Association. Mormon Flat Dam/Canyon Lake, completed in 1926, is located 51 miles northeast of Phoenix. It is a concrete thin arch structure, 224 ft high. Horse Mesa Dam/Apache Lake, completed in 1927, is located 65 miles northeast of Phoenix. It is a concrete thin arch structure, 305 ft high. Stewart Mountain Dam/Saguaro Lake, completed in 1930, is located 41 miles northeast of Phoenix. It is a concrete thin arch structure, 212 ft high. All provide hydroelectric power, recreation, control flooding, and further ensure water for the Phoenix metropolitan area.
graduated in 1926 from the University of Arizona and was appointed to the faculty of Civil Engineering and served continually until 1958. He became a full professor and served as the Dean of the College of Engineering from 1951 to 1958. Along with others from the Arizona Highway Department, and the Bureau of Public Roads, he initiated the Arizona Roads and Streets annual programs.
He was a member of the National Council of State Boards of Engineering Examiners and served as President of the Arizona Section of ASCE in 1939. The ASCE Arizona Section John C. Park Outstanding Engineer Award was established in 1966 to exemplify some of his achievements in professional and personal life.
In 1927 the Office of the State Engineer was replaced by the Arizona Highway Department and the Highway Code was established.
Originally constructed between 1920 and 1928, the bridge spans the Colorado River within the Grand Canyon. At the time of its completion it was the only crossing of the Colorado River in a distance of 754 miles from Moab, Utah to Needles, California. The 440-foot single span suspension bridge provides a connection between the North and South Rims of the Grand Canyon. The structure is suspended from four 550-foot long suspension cables and stabilized by two wind cables. The bridge provides a pathway that is five feet wide. It was designated an ASCE National Historic Civil Engineering Landmark in 2019.
More than a century before Valley residents hopped aboard the high-tech, light-rail system in 2008 for their first ride, streetcar service was offered by the Phoenix Railway Company. The streetcars were powered by mules sauntering up and down Washington Street.
Within years the company added additional routes, some with electric streetcars that tripled the railways speed to 15 mph. By the mid-1920s the system was in need of repairs because of lack of maintenance and shoddy construction. The city purchased the streetcar system and a public bond issue was passed to rehabilitate the streetcar system in 1928. The trolley's end came in 1947 when a fire destroyed most of the railway’s rolling stock, ending 61 years of service.
completed in 1929, is located near Lees Ferry in northern Coconino County. It is one of two bridges bearing this name that carries vehicular traffic on US Route 89A. The 834 ft long steel bridge with its 616 ft three-hinged braced-spandrel arch main span has been judged to be the most historically significant bridge in Arizona. In 1981 it was listed in the National Register of Historic Places, and in 1997 was dedicated as an ASCE National Historic Civil Engineering Landmark. The new Navajo Bridge was built in 1995 to carry modern vehicles more readily with its 44 foot width, compared to the original bridge’s 18 feet. After it opened, the old bridge remained open to pedestrian and equestrian use.
Construction of Sky Harbor Airport was initiated in 1928 and completed in 1929 when it opened. The name was coined by J. Parker Van Zandt, the owner of Scenic Airways. Seeking a base for his company. Van Sandt purchased 278 acres of cotton fields east of 24th Street and south of the Southern Pacific railroad tracks and transformed them into a landing field. By February of 1929, the airport was officially titled Phoenix Sky Harbor Airport. It was sold to a group of local investors in the early 1930s. Facing financial difficulties, Acme pressured Phoenix to buy the airport. The city was initially reluctant to buy the airport, but American Airlines, which had been using Sky Harbor since 1930, threatened to discontinue its passenger and air-mail services there if the city did not take it over. The city purchased the airport for $100,000 in July 1935.
constructed in 1931 and located in Tempe, is one of two bridges bearing this name that carries traffic across the Salt River. It was the major transportation link in three transcontinental highways (US Routes 60, 70 and 80) and Arizona’s only north-south route (US Route 89) until the interstate highway system was begun in the 1950s. The bridge is a ten-span poured concrete, open spandrel structure. The Old Mill Avenue Bridge was listed on the National List of Historic Places in 1981. The New Mill Avenue Bridge, located directly east, upstream, opened in 1994. Construction of the new bride was hampered as flood waters in January 1993 tore down scaffolding and formwork.
Though virtually everyone calls this road the Mt Lemmon Highway or Catalina Highway, its original name was the General Hitchcock Highway in honor of Postmaster General Frank Harris Hitchcock. Work began on the road in 1933 and was completed 17 years later in 1950. The road starts in the Lower Sonoran vegetative life zone and climbs approximately 6000 feet in elevation to the high forests of the Canadian zone, in a short distance of 27 miles. In 1988, the Federal Lands Highway program began a series of seven projects aimed at significantly improving the roadway. The final project was completed in 2007, and the road is now much wider and features adequate shoulders and passing areas. It is designated as a scenic byway by the National Scenic Byways Program and an Arizona Scenic Road by the Federal Highway Administration.
State Bridge Engineer Ralph Hoffman, P.E. (1894-1967) brought innovative design principles to hundreds of bridges constructed in the state during his 34-year tenure with the Arizona Highways Department. 
Several of Hoffman’s recognizable designs like the Tempe (Old Mill Avenue) Bridge were engineering triumphs. The 1,577-foot Tempe Bridge accommodated four highways through the region and served as one of the few crossings over the Salt River for many years. He was responsible for the design of the historic Navajo Bridge. Mr. Hoffman was President of the ASCE Arizona Section in 1933.
On October 1, 1936, the UofA Civil Engineering Department became accredited by the Accreditation Board of Engineering and Technology (ABET), which was formally the Engineering Council for Professional Development (ECPD).
completed in 1936 by a consortium of companies called Six Companies, Inc., is located 30 miles southeast of Las Vegas on the Colorado River on the border between Arizona and Nevada. It is a concrete gravity arch structure, 726 ft high, providing flood control, irrigation water and hydroelectric power. It controlled the powerful Colorado River, opened millions of acres of fertile land for irrigation, and created power and domestic water for the growing cities of the Southwest. It was dedicated by President Franklin D. Roosevelt on September 30, 1935. The project was placed on the list of ASCE National Historic Civil Engineering Landmarks in 1985.
is a concrete slab buttress, ogee weir structure across the California/Arizona border 18 miles northeast of Yuma. Completed in 1938, the 13-foot high dam retains waters of the Colorado River into the Imperial Reservoir before desilting and diversion into the All-American Canal and the Gila Project aqueduct. The gates of three sections hold back the water to help divert the water towards the desilting plant. Three giant desilting basins hold and desilt the water; the removed silt is carried away by sludge pipes running under the Colorado River that dump the sediment into the California sluiceway, which returns the silt to the Colorado River.
completed in 1938, is located 155 miles below Hoover Dam on the Arizona-California border near Parker. It is a concrete gravity arch structure, 85 ft high, but 235 ft below is the riverbed. It is a water source for the Central Arizona Project, and it provides hydroelectric power and irrigation water.
completed in 1938, is located 155 miles below Hoover Dam on the Arizona-California border near Parker. It is a concrete gravity arch structure, 85 ft high, but 235 ft below is the riverbed. It is a water source for the Central Arizona Project, and it provides hydroelectric power and irrigation water.
located 48 miles northeast of Phoenix, was the first dam built on the Verde River. Built by the Bureau of Reclamation, its purpose is to provide flood control and a reservoir of irrigation water for residents of the Salt River Valley and the Salt River Pima Indian Reservation. The design of the dam was completed in the spring of 1936, and a contract was awarded to begin building, but with one proviso: the dam was to be completed in 1,000 days, or by May 9, 1939. The dam was completed on time, and standing 308.5 feet high and 800 feet long, it was the highest multiple arch dam in the world at that time.
During World War II, the United States Army Air Force (USAAF) established numerous airfields in Arizona for training pilots and aircrews of USAAF fighters and bombers. Many were converted into municipal airports, some were returned to agriculture and several were retained as United States Air Force installations and were front-line bases during the cold war. Davis-Monthan Air Force Base (DMAFB) was established in 1925 as Davis-Monthan Landing Field, and from 1940 to 1946 served as a major training base for B-24 and, later, B-29 aircrews. At the end of the war, DMAFB operations were transformed into the unique mission of aircraft storage. The host unit of the base is the 335th Wing, and the base is best known as the location of the boneyard for all excess military and US government aircraft.
In March 1941, some citizens of Mesa were actively working on obtaining a US Army Air Force facility. Agreements were made for a railroad spur line, along with appropriate electric, water, telephone and gas services. In June 1941 the War Department approved the site for a US Army Air Force base. Initial construction was completed in December, making the base operational. It was initially named Mesa Military Airport, but its name was changed to Williams Field. In September 1947 it was re-designated Williams Air Force Base. It was an active training base for both the US Army Air Force, as well as the US Air Force, from 1941 until its closure in 1993. After its closure, the base was annexed by Mesa, and it was converted into the civilian Williams Gateway Airport, later renamed Phoenix-Mesa Gateway Airport.
On February 13, 1941, the War Department approved a site two miles north of Litchfield Park for the construction of an advanced single engine flying training base. Del Webb Corporation broke ground on Litchfield Park Air Base on March 31, 1941, and in June it was renamed Luke Field for 2nd Lt Frank Luke, Jr., a Phoenix native and the first Army aviator to be awarded the Medal of Honor. During World War II, Luke Field produced 17,321 graduates from fighter training programs. The base closed on November 30, 1946. It was redesignated as Luke Air Force Base when it reopened on Feb 1, 1951, in response to a need for fighter aircrews generated by the Korean Conflict. Since then, Luke AFB has been the Air Force’s primary training base for the F-4, F-15 and F-16 aircraft. In 2012 Luke AFB became the F-35A PIlot Training Center.
On April 1, 1942, the Desert Training Center, formed by General George S. Patton, was created. The base was located in the Mojave Desert in Southern California and the Sonoran Desert in western Arizona.
located near Morenci, was converted into an open pit, truck and shovel mine by the Phelps Dodge Corporation in the mid-1940s. Its open pit is 3.3 miles wide in one direction to 4.6 miles in the other direction, extending to a final depth of 4,450 ft. The mine produces 700 to 800 million pounds of copper and 5 to 6 million pounds of molybdenum per year, making it one of the largest open pit mines in the world.
completed in 1946, is located northeast of Phoenix on the Verde River. It is a 144 ft high zoned earth fill embankment. Built by Phelps Dodge Corporation and the Defense Plant Corporation, it provides flood control and irrigation water.
located near Morenci, was converted into an open pit, truck and shovel mine by the Phelps Dodge Corporation in the mid-1940s. Its open pit is 3.3 miles wide in one direction to 4.6 miles in the other direction, extending to a final depth of 4,450 ft. The mine produces 700 to 800 million pounds of copper and 5 to 6 million pounds of molybdenum per year, making it one of the largest open pit mines in the world.
On October 1, 1936, the UofA Civil Engineering Department became accredited by the Accreditation Board of Engineering and Technology (ABET), which was formally the Engineering Council for Professional Development (ECPD).
A new US 60 bridge over Pinto Creek opened on Sept. 17, 2021, with construction beginning in 2012. The bridge is located about six miles west of Miami. It replaced a bridge that opened in 1949 with an estimated lifespan of 50 years. As noted on each end of the old bridge, the American Institute of Steel Construction bestowed an annual award of merit for 1949’s Most Beautiful Steel B, Class II. The new bridge is 695.5 feet in length and is supported by three piers rising as much as 158 feet from the bottom of a deep canyon, topping out roughly at the same level as drivers pass through the area on the existing bridge. The new bridge was constructed within feet of the existing Pinto Creek bridge, which was demolished after the new bridge was fully constructed.
1950
In 1950 the State Aviation Authority was established.
is located 36 miles northwest of Tucson. Initial stripping of the open pit mine started in 1951 and continued until 1984, with leach-precipitation operations continuing. Presently Silver Bell Mining, LLC is owned by Asarco. Annual production is 50 million pounds of copper.
is located 20 miles southwest of Tucson and began operations in 1951. Copper cathode is plated at the nearby Twin Buttes electrowinning facility. Sierrita was operated by Cyprus Mines from 1986 to 1999, by Phelps Dodge Corporation from 1999 to 2007, and subsequently by Freeport-McMoran. Annual production is 100 to 150 million pounds of copper.
is located near San Manuel. Magma Copper Company constructed the mine, plant and railroads and started developing the community of San Manuel in 1952. Open pit operations began in 1985. BHP Billiton purchased the mine in 1995, prior to suspending operations in 1999, and deciding to close the mine and plant sites in 2004.
Sky Harbor Airport began emerging as one of the nation’s major passenger airports in 1952 with the opening of Terminal 1. Built at a cost of $835,000, it was among the most modern and efficient terminals of its time. Terminals were added over time and in 1991 Terminal 1 was demolished.
(1906-1971) was the founder of the engineering consulting firm now known as Carollo Engineers. 
During the 1950s Carollo bought out his partners and the firm eventually became John Carollo Engineers. In this post-war period, Carollo worked closely with Dario Travaini of the City of Phoenix to master plan the city’s water supply and sewerage systems. To reduce the city’s reliance on groundwater, the Verde River Water Treatment Plant was designed in 1949. Much of the City of Phoenix water and wastewater treatment infrastructure was the result of Travaini and Carollo’s forethought. Though he died in 1971, the firm he founded, Carollo Engineers, has offices located across North America, specializing in water, wastewater, and water reuse. Mr. Carollo was President of ASCE Arizona Section in 1943.
are two of 22 flood control dams managed by the Flood Control District of Maricopa County (FCDMC). WT#3 and WT#4 are located in the west valley and were constructed by the Natural Resources Conservation Service (NRCS) in 1954. FCDMC and NRCS in partnership rehabilitated the dams in 2011 and 2017, respectively.
also known as the Mount Lemmon Infrared Observatory, is an astronomical observatory located on Mount Lemmon in the Santa Catalina Mountains approximately 17 miles northeast of Tucson. The site in the Coronado National Forest is used with special permission from the US Forest Service by the University of Arizona’s Steward Observatory and includes eight telescopes that are currently operating. The Mount Lemmon Observatory was first developed in 1954 as a radar installation of the Air Defense Command. Upon transfer to the Steward Observatory in 1970, it was converted to an infrared observatory. Currently the Mount Lemmon SkyCenter, part of the Steward Observatory, operates two telescopes for public use.
(1903-1970) was employed continuously in various capacities by the City of Phoenix from 1931 to 1971. Prior to his service with Phoenix, he was the sanitary engineer for the Grand Canyon National Park and oversaw construction and operation of the sewerage system and preliminary work on the present Grand Canyon water supply. He joined the City of Phoenix in 1931 to manage the completion of the 23rd Avenue Sewage Treatment Plant. He rose to the position of engineer in charge of water and sewers in Phoenix. The title was later changed to Director of Water and Sewers. He was President of the Arizona Section of ASCE in 1954.
Established in 1956.
is a flood control dam located in the west valley of Phoenix, designed and constructed by the US Army Corps of Engineers (USACE) in 1956. Its construction incorporated three existing structures to create an 11-mile-long structure. Its construction was hastened by 7.3 inches of rain in a 24-hour period that flooded Luke Air Force Base and Goodyear in August of 1951. The importance of Luke Air Force Base to the defense of the nation led to congress passing a bill that authorized and funded the construction of the dam. FCDMC, which now manages the dam, constructed the McMicken Dam Fissure Risk Zone Remediation project in 2006 on a segment of the dam at its southern end due to the threat of earth fissures crossing the dam at that location.
(I-17) is a 146-mile-long interstate highway from Flagstaff, at Milton Rd north of I-40, to Phoenix, at I-10/US 60. Most of I-17 is known as the Arizona Veterans Highway. In the Phoenix metropolitan area, it is mostly known as the Black Canyon Highway, however, the southern 4 miles are part of the Maricopa Freeway. In 1956 the Black Canyon Highway from Phoenix to Flagstaff was completed, but not to interstate standards. It was incorporated into the new Interstate Highway System, established by the federal government later that year. The first interchange on the Black Canyon Freeway was built west of downtown Phoenix and was extended to Grand Ave in 1957. The freeway was extended to McDowell Road by 1971 and out of the Phoenix suburbs by 1974. By 1971, I-17 had been completed from Phoenix northward to Camp Verde. The final section of I-17, near Camp Verde, opened to traffic in August 1978.
is a highway in eastern Cochise County that runs from the I-10 junction at Benson to a junction with SR 80 between Bisbee and Tombstone. It has existed since 1957. It is a north-south route north of Sierra Vista and an east-west route east of the city. It heads south of the interchange in Benson towards Kartchner Caverns State Park, then to a junction with SR 82 north of Huachuca City. It passes through the Fort Huachuca Military Reservation, and near Sierra Vista Municipal Airport, then to a junction with SR 92. It continues to the southeast to its eastern terminus.
completed in 1958, is located about 9 miles north of Blythe, CA on the Colorado River. It was constructed as a semi-pervious barrier of sand, gravel and rockfill 46 ft high. It delivers water to the settling basin of the Palo Verde Irrigation District.
(KPNO) is located on Kitt Peak of the Quinlan Mountains 55 miles west-southwest of Tucson. Founded in 1958, it is home to more than twenty optical and two radio telescopes, one of the largest gatherings of astronomical instruments in the northern hemisphere. The observatory was administered by the National Optical Astronomy Observatory (NOAO) from the early 1980s until 2019, after which it was overseen by the National Science Foundation’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab). The largest optical instruments at KPNO are the Mayall 4-meter telescope and the WIYN 3.5-meter telescope; there are also several two- and one-meter class telescopes. The Mayall 4-meter telescope operates on behalf of the Dark Energy Spectroscopic Instrument (DESI) survey, a project led by the US Department of Energy Office of Science.
(FCDMC) was created in 1959 to reduce the risk of flooding to people and property.
On October 1, 1961, the ASU Civil Engineering Department became accredited by the Accreditation Board of Engineering and Technology (ABET).
(AEPCO) is one of two electric cooperatives owned by Arizona G&T Cooperatives. Headquartered in Benson, Arizona G&T Cooperatives also owns and operates Apache Generating Station and Apache Solar in Cochise. Apache Generating Station opened in 1961. AEPCO is the generation, transmission and energy service provider for electric distribution cooperatives and public utilities in Arizona, California and Nevada. Plans include Apache Solar II, which will provide 235 MWac of solar combined with 940 MWh batteries for energy storage. Plans for Apache Generating Station include developing two new gas turbines to assist in modernizing its power generation resources.
in 1962 Arizona State University formed the ASCE student chapter.
Terminal 2 at Sky Harbor Airport opened in 1962, the year that Sky Harbor surpassed the one million passenger mark. Constructed for $2.7 million, comprising 330,000 square feet and 19 gates, Terminal 2 was one of the nation’s most modern facilities. Terminal 2 was remodeled in 2007, with new shops and restaurants and an improved security checkpoint. Terminal 2 was closed and demolished in 2020 after 58 years of service.
The Southern Arizona Branch of the Arizona Section was established in 1962.
In 1962 the State Aviation Authority changed its name to the Arizona Department of Aeronautics.
(1928-2022), with Harold Gerdin, P.E., founded the structural/civil engineering firm Benson and Gerdin, with Roger Benson looking after the structural side and Harold Gerdin the civil side of the business. 
Benson, a graduate of the University of Minnesota, spent 9 or so years working for a design-build firm as an estimator/structural engineer. In 1962 the firm was exploring opportunities in Phoenix. Sometime early in his Phoenix experience, he had the opportunity to supervise other engineers, including Harold Gerdin, and the two recognized an opportunity to provide a multi-discipline engineering firm in Arizona. Eventually a California firm purchased the firm which enabled the two engineers to retire.
(1920-2013), a professional civil engineer, teacher, author and active ASCE member, made outstanding contributions in the areas of hydraulics, water resources planning and environmental issues. She was employed as a hydraulic engineer by the Corps of Engineers for 35 years (1942-1977). In the winter of 1942, she was selected as one of ten draftsmen to go to Panama to complete contract drawings for the Three Locks Project. As chief of various planning sections of the Sacramento District from 1964 to 1977 she was responsible for reservoirs, urban flood control, delta levees, bank protection and navigation channels. Ms. Petersen was an Associate Professor, CEEM, University of Arizona, where she conducted research for the Corps of Engineers on stabilization and rectification of alluvial channels. She was a Distinguished Member of ASCE and recipient of the ASCE Hunter Rouse Hydraulic Engineering Award.
(1927-2001) was the ASCE Arizona Section President in 1965. He was a civil, structural and forensic engineer able to explain complex ideas in simple terms. He served as an AAA arbitrator on many cases.
is located 63 miles south of Flagstaff on a graveled forest road. Originally built by Phelps Dodge Corporation in 1965, ownership of the dam and reservoir was transferred to Salt River Project in 2005, as part of a water-exchange settlement. In addition to satisfying obligations to the Gila River Indian Community, it is used to supplement SRP shareholder’s water supply and to assist in improving the water supply situation in Payson and northern Gila County in accordance with the Arizona Water Settlement Act. The dam is an unsymmetrical thin concrete arch approximately 170 feet high, and with a crest length of 492 feet. The arch varies in thickness from 6 feet at the crest to 14 feet at the base.
was constructed between 1956 and 1966. Named for John Wesley Powell, it is located on the Colorado River near Page. It is a concrete gravity arch structure 710 ft high, and provides hydroelectric power, flood control and water storage. Built for the US Bureau of Reclamation, the dam has been criticized for the large evaporative losses from Lake Powell and its impact on the ecology of the Grand Canyon.
After decades of flooding of central and downtown Tucson because of runoff from Davis-Monthan Air Force Base, the Tucson Diversion Channel project was authorized by Congress in 1948. Construction of the flood control project was initiated in April 1963 and completed in April 1966 to reduce flows upstream from Tucson Arroyo and Railroad Wash drainage areas. A major detention basin was one element of the project, consisting of a 120-acre area enclosed by a 20-foot-high levee. In 1986 the Tucson Detention Basin became an environmental restoration facility named the Ed Pastor Kino Restoration Project.
Located near the intersection of US 60 and Ironwood Road in the far east valley of the Phoenix metro area, a series of earth fissures were detected in the embankment of Powerline FRS, one of 22 flood control dams operated and maintained by the FCDMC. The 2.5-mile-long, 25-foot-high structure was constructed by SCS in 1967 and modified in 1991. The fissures were the result of erosive and collapsing soils and regional differential subsidence caused by groundwater withdrawals. In October of 1972, rainfall events filled the reservoir created by the FRS and two adjacent flood control structures, Vineyard Road FRS and Rittenhouse FRS. The earth fissure risk zone was remediated by trenching and other earthwork, and replacement of sections of the embankment.
(CAP) is a 336-mile-long aqueduct that diverts water from the Colorado River at the Bill Williams Wildlife Refuge portion of Lake Havasu near Parker, into central and southern Arizona. It terminates 14 miles southwest of Tucson. CAP is managed and operated by the Central Arizona Water Conservation District (CAWCD). President Lyndon B. Johnson signed the 1968 Colorado River Basin Project Act authorizing the construction of the CAP. Construction began in 1973 and the CAP was declared substantially complete in 1993. The CAP delivers Arizona’s single largest renewable water supply and serves 80 percent of its population. The 1.4-million-acre feet of water is lifted to elevation 2,900 feet by 14 pumps using 2.5 million MWh of electricity each year, making CAP the largest power user in Arizona.
(1922-2010) served as the ASCE Arizona Section President in 1969. He attended the US Naval Academy and served on the USS New Jersey during World War II. Mr. Dibble founded Dibble and Associates in 1962. He was selected for the ASCE William H. Wisely American Civil Engineer Award in 1990. The honorarium he received for the award was donated to the Arizona Section for the purpose of establishing the Arizona Civil Distinguished Service Award which is awarded annually to an Arizona member of Member grade.
In the 1950s and 1960s there was a need for new electric generation in the Southwest to supply power to growing populations in southern California, Arizona and Nevada. The Bureau of Reclamation also needed a source of power for running the pumps of the planned Central Arizona Project. To fulfill this need, the Navajo Power Project, consisting of the Navajo Generating Station (NGS), along with the Kayenta mine, Black Mesa & Lake Powell Railroad and 800 miles of 500 kV transmission line, was constructed. Bechtel Corporation began construction on the site in 1970. Generating units 1, 2 and 3 were completed in 1974, 1975 and 1976. In 2017, the utility operators of the power station decided to close the facility when the lease expired in 2019. In March of 2019, the Navajo Nation ended efforts to buy the plant and continue running it after the lease expired. On November 18, 2019, the power plant ceased commercial generation.
In 1970 the National Environmental Policy Act was passed.
called the Superstition Freeway, from its connection to I-10 opened in 1970 to Mill Ave as AZ 360. It was gradually extended east to Power Road, which it reached in 1985. At that time traffic had grown so much that the original two-lane road design was inadequate. A third lane and divider wall was added in the median from I-10 to Power Rd. Extending the freeway east to Apache Junction continued in 1989, however, the remaining road was not opened to traffic until the entire 11 miles was completed in 1991. Power Rd to Signal Butte Rd was constructed as three lanes and the remainder as two lanes with a median for future expansion. In 1992 the AZ 360 number was dropped, and freeway interchanges with Loop 101 and Loop 202 were added as these roadways were built. The freeway section ends at Apache Junction.
is a reinforced concrete bridge in Lake Havasu City spanning the Bridgewater Channel Canal that links mainland Lake Havasu City with Pittsburgh Point. When it was built in the 1830s, it spanned the River Thames in London, England. In 1968 the bridge was purchased from the City of London by Robert P. McCulloch. However, McCullogh only had the exterior granite blocks from the original bridge cut and transported to the United States for use in the construction of a new bridge in Lake Havasu City, a planned community he established in 1964 on the shore of Lake Havasu. The bridge was completed in 1971, with the rededication taking place on October 10, 1971. Once completed. a construction company dredged the Bridgewater Channel Canal under the bridge.
(I-8) crosses the Colorado River into Arizona, continues through the city of Yuma and crosses the Sonoran Desert to Casa Grande at I-10. Its length in Arizona is 178 miles. The Arizona portion of the highway was built starting in the 1960s. The route was completed by 1977 through Arizona, though the bridge over the Colorado River was not completed until 1978. By 1964, construction began on the freeway west of Casa Grande, while the rest of the Arizona routing was in design stages. In 1971, I-8 was nearly complete, including a new alignment east of Yuma built parallel and to the south of the original US 80 alignment. A new alignment was also built to the south of the SR 84 alignment at the eastern end of the highway from southwest of Stanfield to the eastern terminus at I-10 southeast of Casa Grande.
In 1972 the Clean Water Act was enacted and regulated pollutants from point sources and established the National Pollutant Discharge Elimination System permit program.
In 1972 the Clean Water Act was enacted and regulated pollutants from point sources and established the National Pollutant Discharge Elimination System permit program.
(I-8) crosses the Colorado River into Arizona, continues through the city of Yuma and crosses the Sonoran Desert to Casa Grande at I-10. Its length in Arizona is 178 miles. The Arizona portion of the highway was built starting in the 1960s. The route was completed by 1977 through Arizona, though the bridge over the Colorado River was not completed until 1978. By 1964, construction began on the freeway west of Casa Grande, while the rest of the Arizona routing was in design stages. In 1971, I-8 was nearly complete, including a new alignment east of Yuma built parallel and to the south of the original US 80 alignment. A new alignment was also built to the south of the SR 84 alignment at the eastern end of the highway from southwest of Stanfield to the eastern terminus at I-10 southeast of Casa Grande.
(I-8) crosses the Colorado River into Arizona, continues through the city of Yuma and crosses the Sonoran Desert to Casa Grande at I-10. Its length in Arizona is 178 miles. The Arizona portion of the highway was built starting in the 1960s. The route was completed by 1977 through Arizona, though the bridge over the Colorado River was not completed until 1978. By 1964, construction began on the freeway west of Casa Grande, while the rest of the Arizona routing was in design stages. In 1971, I-8 was nearly complete, including a new alignment east of Yuma built parallel and to the south of the original US 80 alignment. A new alignment was also built to the south of the SR 84 alignment at the eastern end of the highway from southwest of Stanfield to the eastern terminus at I-10 southeast of Casa Grande.
(I-8) crosses the Colorado River into Arizona, continues through the city of Yuma and crosses the Sonoran Desert to Casa Grande at I-10. Its length in Arizona is 178 miles. The Arizona portion of the highway was built starting in the 1960s. The route was completed by 1977 through Arizona, though the bridge over the Colorado River was not completed until 1978. By 1964, construction began on the freeway west of Casa Grande, while the rest of the Arizona routing was in design stages. In 1971, I-8 was nearly complete, including a new alignment east of Yuma built parallel and to the south of the original US 80 alignment. A new alignment was also built to the south of the SR 84 alignment at the eastern end of the highway from southwest of Stanfield to the eastern terminus at I-10 southeast of Casa Grande.
In 1974 the Arizona Department of Transportation was created. The Arizona Highway Department and the Department of Aeronautics were combined into one multi-modal department.
(1925-2012) was appointed to be the first Director of the Arizona Department of Transportation in 1974, where he served under four governors until his retirement in 1985. He also served as the President of the American Association of State Highway Officials in 1982-1983. When ADOT was created in 1974, it became the first DOT in the nation with its own airport, Grand Canyon National Park Airport, in addition to a new division for public transport.
In 1974 the Safe Drinking Water Act was enacted and regulated source waters and established the National Primary Drinking Water Regulations.
(1924-2001) taught at Arizona State University from 1961 to 1974, advancing to professor and Civil Engineering Department chairman. During this time, he received his Doctorate from Northwestern University. He relocated to Los Angeles and worked as a senior engineer for Dames and Moore until 1979 when he returned to Phoenix and became director of the Central Arizona Water Control Study until late 1982. He received the John C. Park award as Outstanding Civil Engineer in 1985. He was a member of the Arizona Society of Civil Engineers and chairman of the Accreditation Board for engineering and technology.
is a flood control dam designed and constructed by the US Army Corps of Engineers in 1974 with the FCDMC as the local sponsor. The dam is located on Dreamy Draw Wash just east of Highway 51 and was designed to detain floodwater runoff from the Phoenix Mountains. Contrary to local folklore, the dam was not built to cover up a UFO crash site from 1947. Officials that manage the dam indicate that “The story is fictional , but it appears that the myth is alive and well.”
On October 1, 1974, the Northern Arizona University (NAU) Civil Engineering Department became accredited by the Accreditation Board of Engineering and Technology (ABET).
are three hydraulically connected flood control dams constructed by the National Resource Conservation Service (NRCS) in 1974, 1975 and 1975, respectively. The three dams provide flood protection to the City of Buckeye. Buckeye FRS #1 was modified in 1980 by FCDMC, a local sponsor. These dams are located just east of the Hassayampa River, north of I-10. A 2004 investigation of Buckeye FRS #1 determined the structure had experienced both longitudinal and transverse cracking because of differential subsidence of the FRS. This led to the rehabilitation of the FRS by placing a new central filter with a downstream geotextile. Its overall rehabilitation was completed in 2024 by FCDMC in partnership with NRCS.
1975
(1924-2013) served as the Public Works Director and County Engineer of Maricopa County beginning in 1969. Prior to that he served as the City Engineer of Phoenix. He enlisted in the Navy in 1942, which began a 42-year commitment to the navy, active duty and reservist, culminating with his promotion to Flag rank, commanding all Naval Reservists construction and civil engineering in the Western United States. Mr. Esterbrooks was awarded the honor of Urban Engineer of the Year in 1983 by the National Association of County Engineers. He was president of the Arizona Section of ASCE in 1975. He was elected the National President of APWA and served as a National Director of ASCE from 1983 to 1986.
(1924-2013) served as the Public Works Director and County Engineer of Maricopa County beginning in 1969. Prior to that he served as the City Engineer of Phoenix. He enlisted in the Navy in 1942, which began a 42-year commitment to the navy, active duty and reservist, culminating with his promotion to Flag rank, commanding all Naval Reservists construction and civil engineering in the Western United States. Mr. Esterbrooks was awarded the honor of Urban Engineer of the Year in 1983 by the National Association of County Engineers. He was president of the Arizona Section of ASCE in 1975. He was elected the National President of APWA and served as a National Director of ASCE from 1983 to 1986.
In 1976, construction began on the $35 million Terminal 3 at the Sky Harbor International Airport and its $13 million parking garage. At that time 4.4 million people were flying in and out of the airport annually. After Terminal 3 opened in 1979, passenger traffic grew to 7 million. By the end of 1985, passenger traffic at Terminal 3 had grown to 11.6 million. A remodeling project completed in 1997 renovated the second level lobby and concession area and added 11 new shops. A $590 million modernization completed in 2020 included opening of a new security checkpoint and ticket counters in 2016, a South Concourse in 2019, and the reopening of a renovated North Concourse in 2020.
are flood control dams constructed by NRCS in 1975 and 1976, respectively, with FCDMC as the local sponsor. The small dams are located in the Wickenburg area.
are three hydraulically linked flood control dams constructed by the Soil Conservation Service, now the National Resource Conservation Service, with FCDMC as the local sponsor. These dams, constructed in 1976, 1988 and 1988, respectively, are located east of Apache Road and north of Apache Trail. The dams, managed by the FCDMC, provide flood protection to east Mesa and Apache Junction. The overall rehabilitation of Spook Hill FRS, including construction of a new concrete dam and building a new central filter in the existing dam, was completed in 2018 by the Arizona Department of Transportation in partnership with FCDMC as part of the Loop 202 freeway project.
(1918-2012), a 1942 University of Arizona graduate, spent the next four years serving in the Navy as a member of the SeaBees Construction Battalion. He then began his 34-year career with the Arizona Highway Department. 
He was part of the reorganization that created the Arizona Department of Transportation (ADOT). He continued to advance his career until he became the Arizona State Highway Engineer in 1977. During his stay with the department, he worked on some of its largest projects, including implementing one of the major engineering projects in the US, the Virgin River Gorge along Interstate 15 in northwest Arizona. Looking for new challenges, he entered private consulting in 1980. He was an active participant in ASCE, serving as a National Officer Director, and in 1964 as Arizona Section President. He also served at a national level in associations and societies such as AASHTO and NSPE.
The Northern Arizona Branch of the Arizona Section of ASCE was established in 1979.
The 1980 Arizona Groundwater Code recognized the need to aggressively manage the state’s finite groundwater resources to support the growing economy. Areas with heavy reliance on mined groundwater were identified and designated as Active Management Areas (AMAs). Currently there are six AMAs (Prescott, Phoenix, Pinal, Tucson, Santa Cruz and Douglas) which are subject to regulation pursuant to the Groundwater Code.
the first greenbelt to be constructed in Arizona, was completed in 1980 after twelve years of planning and construction. The 11.8-mile-long greenbelt features a string of five parks, four golf courses, and lakes connected by a network of bicycle and pedestrian paths that run without interruption, thanks to 24 grade separated crossings. The north section extends 4.5 miles from Venturoso Park, at N 32nd Street and Thunderbird Rd, to Shea Blvd and N 54th Street. After a 5-mile gap, the south section runs for 7.3 miles from Indian Bend Road to Tempe Town Lake, passing through Chapparal Park, Camelback Park, Eldorado Fields and McKellips Lake.
The Arizona Department of Water Resources was created in 1980.
is a flood control dam designed and constructed by the US Army Corps Of Engineers in 1982 with FCDMC as the local sponsor. The dam, managed by FCDMC, is located on Skunk Creek just east of SR 101. There are numerous recreational facilities and activities located upstream of the dam in the impoundment area which are managed by Maricopa County Parks Department under agreement with FCDMC. All of these facilities and activities are managed to be fully compatible with the safe and proper operation and maintenance of the dam.
(1927-2013), a renowned groundwater hydrologist, was the Director of the US Water Conservation Laboratory in Phoenix from 1972 to 1990. He was involved with water resources management, with a specialization in the area of Managed Aquifer Recharge (MAR). He won the ASCE Walter Huber Research prize in 1966, and the ASCE R. J. Tipton award in 1984.
In 1984, Tucson Water launched the utility’s Reclaimed Water Treatment Plant and the Sweetwater Recharge Facility with 10 miles of pipeline serving one customer, La Paloma, a destination golf course. There are multiple Tucson Water reclaimed facilities that provide a combination of aquifer recharge, recovery or direct delivery of highly treated wastewater to Arizona Class A+ standards. These include the Santa Cruz River Managed Underground Storage Facility (1999), the Lower Santa Cruz River Managed Recharge Project (2003), the Santa Cruz River Heritage Project (2019), and the Southeast Houghton Area Recharge Project (SHARP, 2023).
(1933-2000) was an educator at Arizona State University from 1964 to 1997, where he rose to be Chair of the Civil Engineering Department. He was a geotechnical engineer who was awarded the Outstanding Engineering Educator’s award by the governor in 1986. He also was Chair of the Arizona State Board of Technical Registration.
established in 1987.
(1936-2015), taught geotechnical engineering at the University of Arizona. He was President of the Arizona Section of ASCE in 1987 and was Chair of the ASCE Committee on Curricula and Accreditation.
(SR 101 or Loop 101) was part of the 1985 Maricopa County Regional Transportation Plan that was funded by a sales tax approved by Maricopa County voters that year. Loop 101 is comprised of three sections: the Aqua Fria Freeway begins at a three level interchange in Tolleson and ends at its intersection with I-17 15 miles north of downtown Phoenix; it continues as the Pima Freeway terminating at its intersection with the Red Mountain Freeway, which was partially built over the Salt River; then it becomes the Price Freeway continuing south before concluding at an interchange with the San Tan Freeway portion of Loop 202. The 61 mile Loop 101 was built in stages from 1988 to 2002, including interchanges with I-10, I-17, both Loop 202 Freeways, and US 60.
(SR 101 or Loop 101) was part of the 1985 Maricopa County Regional Transportation Plan that was funded by a sales tax approved by Maricopa County voters that year. Loop 101 is comprised of three sections: the Aqua Fria Freeway begins at a three level interchange in Tolleson and ends at its intersection with I-17 15 miles north of downtown Phoenix; it continues as the Pima Freeway terminating at its intersection with the Red Mountain Freeway, which was partially built over the Salt River; then it becomes the Price Freeway continuing south before concluding at an interchange with the San Tan Freeway portion of Loop 202. The 61 mile Loop 101 was built in stages from 1988 to 2002, including interchanges with I-10, I-17, both Loop 202 Freeways, and US 60.
(SR 101 or Loop 101) was part of the 1985 Maricopa County Regional Transportation Plan that was funded by a sales tax approved by Maricopa County voters that year. Loop 101 is comprised of three sections: the Aqua Fria Freeway begins at a three level interchange in Tolleson and ends at its intersection with I-17 15 miles north of downtown Phoenix; it continues as the Pima Freeway terminating at its intersection with the Red Mountain Freeway, which was partially built over the Salt River; then it becomes the Price Freeway continuing south before concluding at an interchange with the San Tan Freeway portion of Loop 202. The 61 mile Loop 101 was built in stages from 1988 to 2002, including interchanges with I-10, I-17, both Loop 202 Freeways, and US 60.
The Inner Loop of I-10 begins with the symmetrical four level I-17/US 60 interchange known as the Stack, continues due east then south until reaching the second junction with I-10/US 60. Three miles northwest of that intersection, I-10 enters another interchange for SR 51 and Loop 202 called the Mini Stack. Near 3rd Ave, the highway enters the half-mile Papago Freeway Tunnel, known as the Deck Park Tunnel. The underpass was the last section of I-10 to be completed nationwide. The initial plan to construct the Inner Loop, developed in the 1960s, involved an elevated freeway 10 stories high, but it became very controversial among Phoenix residents. A majority of voters approved a below grade freeway that included a tunnel. Construction of the Inner Loop began in 1983 and it was finished in August 1990.
established in 1987.
The Inner Loop of I-10 begins with the symmetrical four level I-17/US 60 interchange known as the Stack, continues due east then south until reaching the second junction with I-10/US 60. Three miles northwest of that intersection, I-10 enters another interchange for SR 51 and Loop 202 called the Mini Stack. Near 3rd Ave, the highway enters the half-mile Papago Freeway Tunnel, known as the Deck Park Tunnel. The underpass was the last section of I-10 to be completed nationwide. The initial plan to construct the Inner Loop, developed in the 1960s, involved an elevated freeway 10 stories high, but it became very controversial among Phoenix residents. A majority of voters approved a below grade freeway that included a tunnel. Construction of the Inner Loop began in 1983 and it was finished in August 1990.
is a flood control dam designed and constructed by the US Army Corps Of Engineers in 1982 with FCDMC as the local sponsor. The dam, managed by FCDMC, is located on Skunk Creek just east of SR 101. There are numerous recreational facilities and activities located upstream of the dam in the impoundment area which are managed by Maricopa County Parks Department under agreement with FCDMC. All of these facilities and activities are managed to be fully compatible with the safe and proper operation and maintenance of the dam.
(1934-2015) was an educator, teaching transportation engineering at the University of Arizona. He was the Director of District 11 of ASCE and was Chairman of the ASCE Highway Division Executive Committee. From 1993 to 1995, he served on ASCE’s Board of Direction.
is a flood control dam designed and constructed by the US Army Corps Of Engineers in 1982 with FCDMC as the local sponsor. The dam, managed by FCDMC, is located on Skunk Creek just east of SR 101.
There are numerous recreational facilities and activities located upstream of the dam in the impoundment area which are managed by Maricopa County Parks Department under agreement with FCDMC. All of these facilities and activities are managed to be fully compatible with the safe and proper operation and maintenance of the dam.
is a flood control dam designed and constructed by the US Army Corps Of Engineers in 1982 with FCDMC as the local sponsor. The dam, managed by FCDMC, is located on Skunk Creek just east of SR 101. There are numerous recreational facilities and activities located upstream of the dam in the impoundment area which are managed by Maricopa County Parks Department under agreement with FCDMC. All of these facilities and activities are managed to be fully compatible with the safe and proper operation and maintenance of the dam.
is a flood control dam designed and constructed by the US Army Corps Of Engineers in 1982 with FCDMC as the local sponsor. The dam, managed by FCDMC, is located on Skunk Creek just east of SR 101. There are numerous recreational facilities and activities located upstream of the dam in the impoundment area which are managed by Maricopa County Parks Department under agreement with FCDMC. All of these facilities and activities are managed to be fully compatible with the safe and proper operation and maintenance of the dam.
The Inner Loop of I-10 begins with the symmetrical four level I-17/US 60 interchange known as the Stack, continues due east then south until reaching the second junction with I-10/US 60. Three miles northwest of that intersection, I-10 enters another interchange for SR 51 and Loop 202 called the Mini Stack. Near 3rd Ave, the highway enters the half-mile Papago Freeway Tunnel, known as the Deck Park Tunnel. The underpass was the last section of I-10 to be completed nationwide. The initial plan to construct the Inner Loop, developed in the 1960s, involved an elevated freeway 10 stories high, but it became very controversial among Phoenix residents. A majority of voters approved a below grade freeway that included a tunnel. Construction of the Inner Loop began in 1983 and it was finished in August 1990.
is a flood control dam designed and constructed by the US Army Corps Of Engineers in 1982 with FCDMC as the local sponsor. The dam, managed by FCDMC, is located on Skunk Creek just east of SR 101. There are numerous recreational facilities and activities located upstream of the dam in the impoundment area which are managed by Maricopa County Parks Department under agreement with FCDMC. All of these facilities and activities are managed to be fully compatible with the safe and proper operation and maintenance of the dam.
is a flood control dam designed and constructed by the US Army Corps Of Engineers in 1982 with FCDMC as the local sponsor. The dam, managed by FCDMC, is located on Skunk Creek just east of SR 101. There are numerous recreational facilities and activities located upstream of the dam in the impoundment area which are managed by Maricopa County Parks Department under agreement with FCDMC. All of these facilities and activities are managed to be fully compatible with the safe and proper operation and maintenance of the dam.
2000
In 1972 the Clean Water Act was enacted and regulated pollutants from point sources and established the National Pollutant Discharge Elimination System permit program.a project aimed to restore the natural riparian habitat along a five-mile reach of the Salt River in Phoenix began in June 2000. The project involved the City of Phoenix, the US Army Corps of Engineers, the Flood Control District of Maricopa County, and other local and federal organizations. Restoration included the removal of 1,185 tons of tires and other debris, channelization of a low-flow channel along the reach to safely convey nuisance flows, restoration of a natural habitat, and development of trails for biking, hiking and other recreational activities.
In 1972 the Clean Water Act was enacted and regulated pollutants from point sources and established the National Pollutant Discharge Elimination System permit program.a project aimed to restore the natural riparian habitat along a five-mile reach of the Salt River in Phoenix began in June 2000. The project involved the City of Phoenix, the US Army Corps of Engineers, the Flood Control District of Maricopa County, and other local and federal organizations. Restoration included the removal of 1,185 tons of tires and other debris, channelization of a low-flow channel along the reach to safely convey nuisance flows, restoration of a natural habitat, and development of trails for biking, hiking and other recreational activities.
In 1972 the Clean Water Act was enacted and regulated pollutants from point sources and established the National Pollutant Discharge Elimination System permit program.a project aimed to restore the natural riparian habitat along a five-mile reach of the Salt River in Phoenix began in June 2000. The project involved the City of Phoenix, the US Army Corps of Engineers, the Flood Control District of Maricopa County, and other local and federal organizations. Restoration included the removal of 1,185 tons of tires and other debris, channelization of a low-flow channel along the reach to safely convey nuisance flows, restoration of a natural habitat, and development of trails for biking, hiking and other recreational activities.
In 1972 the Clean Water Act was enacted and regulated pollutants from point sources and established the National Pollutant Discharge Elimination System permit program.a project aimed to restore the natural riparian habitat along a five-mile reach of the Salt River in Phoenix began in June 2000. The project involved the City of Phoenix, the US Army Corps of Engineers, the Flood Control District of Maricopa County, and other local and federal organizations. Restoration included the removal of 1,185 tons of tires and other debris, channelization of a low-flow channel along the reach to safely convey nuisance flows, restoration of a natural habitat, and development of trails for biking, hiking and other recreational activities.
was enacted in 2006, increasing monitoring and regulations for systems using groundwater as a drinking water source.
was enacted in 2006, increasing monitoring and regulations for systems using groundwater as a drinking water source.
In 1972 the Clean Water Act was enacted and regulated pollutants from point sources and established the National Pollutant Discharge Elimination System permit program.a project aimed to restore the natural riparian habitat along a five-mile reach of the Salt River in Phoenix began in June 2000. The project involved the City of Phoenix, the US Army Corps of Engineers, the Flood Control District of Maricopa County, and other local and federal organizations. Restoration included the removal of 1,185 tons of tires and other debris, channelization of a low-flow channel along the reach to safely convey nuisance flows, restoration of a natural habitat, and development of trails for biking, hiking and other recreational activities.
built between 2005 and 2010, is located within the Lake Mead Recreation Area 30 miles southeast of Las Vegas. The bridge carries US 93 over the Colorado River. It is a key component of the Hoover Dam Bypass project, which rerouted US 93 from its routing along the top of Hoover Dam and removed several hairpins and blind curves from the route. The bypass project included new approach bridges in both Arizona and Nevada.
In 1972 the Clean Water Act was enacted and regulated pollutants from point sources and established the National Pollutant Discharge Elimination System permit program.a project aimed to restore the natural riparian habitat along a five-mile reach of the Salt River in Phoenix began in June 2000. The project involved the City of Phoenix, the US Army Corps of Engineers, the Flood Control District of Maricopa County, and other local and federal organizations. Restoration included the removal of 1,185 tons of tires and other debris, channelization of a low-flow channel along the reach to safely convey nuisance flows, restoration of a natural habitat, and development of trails for biking, hiking and other recreational activities.
In 1972 the Clean Water Act was enacted and regulated pollutants from point sources and established the National Pollutant Discharge Elimination System permit program.a project aimed to restore the natural riparian habitat along a five-mile reach of the Salt River in Phoenix began in June 2000. The project involved the City of Phoenix, the US Army Corps of Engineers, the Flood Control District of Maricopa County, and other local and federal organizations. Restoration included the removal of 1,185 tons of tires and other debris, channelization of a low-flow channel along the reach to safely convey nuisance flows, restoration of a natural habitat, and development of trails for biking, hiking and other recreational activities.
also known as the Tucson Modern Streetcar, is a single-line streetcar system in Tucson that began service in 2014. The 3.9-mile alignment improves connectivity between the University of Arizona and downtown, with 23 stops and frequency of operation of 10 minutes during the day and during the evening. Originally conceived in 1994, the $196 million project’s cost was met through a combination of local funding sources and federal grants. In 2006, Pima County voters approved a 20-year regional transportation plan that included $88 million toward the construction and operation of Sun Link. In 2010, a $63 million federal TIGER grant was awarded to Tucson, meeting most of the remaining funding gap and allowing the project to move forward.
Cochise County since 2015 has been a key partner in the Cochise Conservation and Recharge Network (CCRN) along with the cities of Sierra Vista and Bisbee, The Nature Conservancy, the Bureau of Land Management, Fort Huachuca, and the Hereford Natural Resource Conservation District. CCRN is an innovative series of projects capable of increasing flows in the upper San Pedro River, conserving groundwater and improving the health of habitat. The regional network of projects includes the Palominas Flood Control and Recharge Project, which serves as a model for additional recharge projects along the river. The regional network of projects encompasses 6,344 acres of land along 25 miles of the river where replenishment can most benefit the flows of the river.
opened in 2006 as Cardinals Stadium. Later that year the University of Phoenix acquired naming rights, renaming it University of Phoenix Stadium, in what was then a 20-year agreement. It was renamed in September 2018 for the insurance company State Farm, which has an 18-year naming rights deal. The stadium is a multi-purpose retractable roof stadium in Glendale. It replaced Sun Devil Stadium in Tempe as the home of the Cardinals. The stadium has been the host of the Fiesta Bowl since 2007 and hosted BCS national championship games in 2007 and 2011. It hosted the college football national championship in 2016, three super bowls (2008, 2015 and 2023), and the pro bowl in 2015. For basketball it hosted the NCAA Men’s Final Four in 2017 and 2024. It has been the host of various shows, expositions, tradeshows and motor sports events, and more.
became a real loop in 2018 when Pima County completed a connection on the south bank of the Rillito River Park that connected the Rillito River to the Pantano River Park. Connecting the Santa Cruz River Park with the Rillito River, Pantano, Harrison Greenway and Julian Wash makes a complete circuit of 53.9 miles. The Loop extends through unincorporated Pima County, Oro Valley, Tucson, and South Tucson. The Loop is the culmination of a 35 year long continual effort to implement a river parks system along major streams. A system of paved, shared-use paths and short segments of buffered bike lanes connecting the Canada del Oro, Rillito, Santa Cruz, and Pantano River Parks with Julian Wash and Harrison Road Greenway has been completed.
has been home to the Advanced Water Treatment Facility (AWT), one of the most sophisticated recycled water facilities in the world. It is the first permanent facility in Arizona permitted as a pilot program in 2019 for advanced water purification. AWT is one of the largest potable water purification facilities in the world and can treat up to 20 million gallons of recycled water a day to a water quality standard that exceeds that of bottled water. AWT has been performing indirect potable reuse (recharging ultra-purified water into the drinking water aquifer) for more than 30 years. The facility takes treated recycled water from the city’s conventional water reclamation plant and further treats it through ozonation, membrane ultrafiltration, reverse osmosis and ultraviolet photolysis.
(SR 202 or Loop 202) has three officially designated sections along its route: the Red Mountain Freeway from the mini stack interchange with I-10 and SR-51 in Phoenix to the SuperRedTan Interchange with US 60 in Mesa; then the San Tan Freeway extending to the east to an interchange with I-10; then the Congressman Ed Pastor freeway extending to the east and north to its end at an interchange with I-10. The Red Mountain Freeway section opened in July 2008, thus marking the completion of the original Regional Freeway System as approved by Maricopa County voters in 1985 as Proposition 300. The San Tan Freeway was completed in 2006. The third and final leg of Loop 202, the Congressman Ed Pastor Freeway, with construction completed at the end of 2019. The 21.9-mile section underwent years of controversy between ADOT, the Gila River Indian Community (GRIC), the EPA and other groups, before receiving a record of decision from FHWA approving the project and selecting a build alternative.
With the extension of the sales tax approved in 2004, State Route 303 (SR 303 or Loop 303) was added by ADOT to the regional transportation plan. Originally it was a part of the Maricopa County Regional Transportation Plan. Originally designated SR 517 in 1985, the Loop 303 designation was first assigned in 1987. The interim two-lane highway was completed between US 60 and I-10 in 1991. The freeway was scheduled to be completed by 2005, however, funding shortfalls and increased construction costs forced it to be dropped from regional plans in 1995. Construction on the freeway proceeded in 2004 with a planned completion date of the I-10 to I-17 segment in 2015. In 2011 ADOT began upgrading Loop 303 between US 60 and I-10 from a two-lane highway to a six-lane freeway, with construction completed in 2013. With the addition of interchanges and additional lanes, Loop 303 was fully upgraded to freeway standards between I-10 and I-17 by 2020.
2025
The Arizona Section of the
American Society of Civil Engineers
would like to
give special thanks to:
Lawrence A. Hansen, PhD, PE
Historical Record Search
& Timeline Subcommittee Chair
Elizabeth Olaiz-Rockwell, PE, MBA, CFM
Centennial Committee Graphic Designer
Austin Olaiz-Rockwell, PhD, PE
Centennial Timeline Website Developer
as well as the following
companies, organizations, and people
who contributed to the timeline development:
Arizona Historical Society
Arizona Department of Transportation
United States Bureau of Reclamation
Salt River Project
Arizona Public Service
Palo Verde Generating Station
City of Phoenix
Central Arizona Project
Flood Control District of Maricopa County
University of Arizona Libraries
University of Arizona Civil & Architectural Engineering and Mechanics
Arizona State University School of Sustainable Engineering and the Built Environment
Civil Engineering Magazine staff
Pima County
Carollo Engineers
Dibble Corporation
HNTB Corporation
Carey Kyler (daughter of Charles O’Bannon)
Bob Ribokas/Grand Canyon Explorer
James Bell Girand Family
Hoffman Collection/Mary Lou Vaughn
The Bolton Company/Randy Irvine & Norm Arnold
TwinPinShare/ADOT
Mariordo Roberto Duran Ortiz
Larry Hanson
Historical Record Search & Timeline subcommittee members:
Benny Young
Seth Chalmers
Enamul Hoque