Allentown Bridge
a.k.a. Rio Puerco Bridge
Indian Rt. 9402 over Puerco River, milepost 9.1, Houck, AZIn 1922, the Arizona Highway Department began the major reconstruction of the Holbrook-Lupton Highway between Adamana and the state line. Two critical components of the project were the erection of substantial bridges over the Rio Puerco near the small Indian settlements of Allentown and Sanders. For the Allentown Bridge, AHD staff engineers designed a medium-span deck truss with 20' cantilevered ends. Using money from the state road fund and an Apache County bond issue, AHD let the contracts for the Sanders and Allentown bridges and a small pony truss over Lupton Arroyo at Lupton on January 1, 1923. The Midland Bridge Company of Denver was awarded the contract for the Allentown bridge. Midland began construction of the bridge on January 17 and, using steel milled by Illinois, completed the structure on July 11. Total construction cost: $11,675. Both the Allentown and Sanders crossings were removed from the highway by another realignment in 1931, and the bridges have since carried local traffic on the Navajo Indian Reservation.
Later designated U.S. Highway 66, the Santa Fe Highway was a major transcontinental route across northern Arizona. Before the construction of this bridge, traffic on the highway often was forced to wait up to 24 hours for the Rio Puerco to subside enough to permit fording. The Allentown Bridge thus formed an important link on a major interstate route. The Allentown Bridge is further significant as one of the earliest deck trusses built by the State Engineer, erected by a regionally active bridge contractor. Technologically, the Allentown Bridge is distinguished as one of the two earliest deck trusses identified in the inventory (other:Little Hell Canyon Bridge, 1923). Its cantilevered ends are unique among Arizona's vehicular trusses, but by no means technologically noteworthy.
Listed in National Register of Historic Places in 1988.
The National Register of Historic Places is the official list of the Nation’s historic places worthy of preservation. Authorized by the National Historic Preservation Act of 1966, the National Park Service’s National Register of Historic Places is part of a national program to coordinate and support public and private efforts to identify, evaluate, and protect America’s historic and archeological resources.