The Salt River is formed in eastern Arizona where the Black and White rivers join in Gila County. Slowed by a handful of dams on the way, the Salt River reaches the Phoenix metro area, providing a precious water supply to the arid megalopolis. Pictured here is the Mill Avenue Bridge in Tempe, one of the earliest bridges to cross the Salt River. Designed in 1929, the poured concrete structure utilizes a series of graceful spandrels, each 140 feet long, supporting the roadbed. Abutment piers rise up over the roadbed to create pedestrian rest areas, shaded by a canopy. For eighty years its support piers have withstood a seasonal onslaught of torrential currents. In 1980, floodwaters raged throughout the Salt River Valley, sending more than twice the amount of water the bridge was designed to withstand.
     A sister bridge was erected in 1994, converting each bridge to multiple lane, one way traffic. In 1999, the dry river crossing was closed and the river dammed, creating Tempe Town Lake. Part of a revitalization project of Downtown Tempe, the lake and bridges are centerpieces for a new Tempe, and the Tempe Town Lake Festival.