The Antelope Hill Highway Bridge (also known as the Antelope Hill Bridge) is a historic bridge over the Gila River in Tacna, Arizona, U.S. It was built between 1914 ad 1915 as a ten-span concrete girder bridge. The bridge served as an integral piece of the Ocean to Ocean Highway between Yuma and Phoenix from 1915 to 1922, when it was bypassed by an alternate route through Gila Bend, paralleling the Gillespie Dam. The bridge and original highway were bypassed mainly due to damage caused by flooding along the river floodplain it was constructed on. After being repurposed for traffic traveling north from Yuma, the bridge was finally abandoned in 1929 following completion of the McPhaul Suspension Bridge. The ruins of the old bridge are currently listed on the National Register of Historic Pla