Gillespie Dam Bridge, Spanning Gila River on Old US 80 Highway, south of Gillespie Dam, Arlington, Maricopa County, AZ

Significance: Prior to completion of this bridge in 1927, traffic on the Pikes Peak Ocean-to-Ocean Highway at this point was often halted by flooding on the Gila River. The Gillespie Dam Bridge was this strategically important to Arizona transportation in that is finally allowed all-weather travel over this vital transcontinental route. Technologically, the bridge is noteworthy as one of the longest vehicular structures in the state. Arizona's longest bridges have historically been built over the Gila. In fact, more effort and money was spent building and maintaining bridges over the Gila than any other river in the state. Of the five longest vehicular structures in the state in 1927, four spanned the Gila. Of these, the Gillespie Dam Bridge was the only steel structure. Several multiple-span vehicular through trusses were erected in the state in the 1910s and 1920s, but through attrition only two exist today the Gillespie Dam Bridge and the Boulder Creek (Wickenburg) Bridge. In almost unaltered condition today, the Gillespie Dam Bridge is one of the most important examples of early bridge construction in Arizona.
Unprocessed Field note material exists for this structure: N1115
Survey number: HAER AZ-69
Building/structure dates: after. 1925- before. 1928 Initial Construction