Gillespie Dam Bridge still standing

Gillespie Dam Bridge still standing

Kathy Cline/ADOT Communications
October 24, 2021

It may not look like much from afar ... but the Gillespie Dam bridge is a survivor in one of the most notorious bridge-problem areas in Arizona.

Building on the Gila River has always been a challenge. The floodplain is a very turbulent one, and the Antelope Hill bridge (the original site for a bridge across the river) sustained severe damage time and again from floods. In addition, continual flood damage to the newly-established Ocean-to-Ocean Highway led state officials to reroute the road between Wellton and Arlington (south of the river, through Gila Bend). However, since Arlington was north of the river, a new crossing had to be built.

After a few years of problems and false starts (including a flood that washed away much of the construction equipment and materials), the Gillespie Dam Bridge was opened for traffic in 1927. It remained part of the old U.S. 80 mainline until 1956, when the road was re-aligned. It now functions as a county bridge and is part of Historic U.S. Route 80.

The Gillespie Dam bridge was one of the longest vehicular structures in Arizona when it was originally built; it was also the only steel bridge across the Gila River, and one of two remaining bridges with multi-span vehicular through trusses. The Gila River Flood of 1993 only caused some support piers to settle (because of its design and concrete support piers sunk in bedrock). It's one of the most important examples of early bridge construction in Arizona.