In July 1949 the Arizona Highway Department began production of construction drawings for a large-scale bridge that would carry the Safford-Clifton Highway (State Highway 'E'1) over the Gila River. Located near Guthrie, the proposed bridge would carry the road on a high line over a broad ravine. As delineated by AHD, the Guthrie Bridge was configured as a three-span Pratt deck truss with riveted connections. The distance between the superstructure and the riverbed below was too great to allow for traditional erection false- work, so AHD designed the Guthrie Bridge as a cantilever truss, with a long central span counterbalanced on either end by shorter anchor spans. The center span extended 300 feet over the river's main channel; the approach spans extended about 100 feet each and were in turn approached by steel girders, the longest of which reached 60 feet. The superstructure was held aloft by concrete pedestals on spread footings. The trusses and girders carried a concrete deck on steel stringers, which was bounded on both sides by aluminum beam guardrails. AHD designated the project as non-Federal Aid Secondary Project 46 and on March 24, 1949, awarded a contract for the bridge's construction to the Vinson Construction Company. The Phoenix- based contractors started work on the substructural excavation that spring. They completed the bridge in 1950 for an aggregate cost of almost $350,CIl0. The Guthrie Bridge was massive, consuming almost 1,500 cubic yards of concrete, 190,000 pounds of reinforcing steel and 1 million pounds of structural steel. It carried high- way traffic, first on SH 71, later on US 666 and most recently on US 191. Today the bridge function in unaltered condition.
As a pivotal crossing on a regionally important route, the Guthrie Bridge enjoys a degree of significance for its contribution to southern Arizona transportation. The bridges relatively late construction limits this significance, however. The structure is technologically important as a well-preserved example of large-scale bridge construction. Arizona erected a number of massive steel arches and cantilevered steel deck trusses in the 1940s and 1950s, most of which are impressively scaled spans placed in dramatic settings. A handful of these remain: the Queen Creek Bridge  in Pina County and the Pinto Creek Bridge  in Gila County representing the arches, and the Guthrie Bridge, the Hell Canyon Bridge  in Yavapai County, and the Cameron Bridge [05321 in Coconino County representing the trusses. These were the state's most striking bridges of post-War period. AHD engineers were clearly concerned with the proportions and detailing of the Guthrie Bridge, producing a perspective rendering of it as part of the construction documents. With its clean proportions and grand scale, it numbers among Arizona's most spectacular steel spans.