Mill Avenue @ Rio Salado
Tempe, AZ 85281
CATEGORY: Historical Properties
YEAR BUILT: 1931
The Mill Avenue Bridge is the second oldest automobile crossing on the Salt River in the Phoenix metropolitan area, and has been in continuous use since its completion in 1931. It was the major transportation link in three transcontinental highways (U.S. Routes 60, 70, and 80) and Arizona’s only north-south route, U.S. Route 89, until the freeway system was begun in the 1950s. The bridge was built to replace an earlier highway bridge built twenty years earlier at Ash Avenue but had become increasingly congested and was no longer able to adequately support wider and heavier vehicles. In 1928, a group of Tempe businessmen submitted a request to the Arizona Highway Commission that a new bridge be planned. The bridge was designed by the Arizona Highway Department in 1929. Ralph Hoffman, the bridge engineer for the State of Arizona, signed the contract with Lynch-Cannon Construction Company of Los Angeles, implementing Federal Project 2-B. The bridge was opened to traffic in August of 1931, but was not officially dedicated until 1933. Presiding at the ceremony was Arizona Governor B. B. Moeur, a Tempe physician.