What type of bridge is the historic Canyon Diablo Bridge that once carried Route 66 near Two Guns, Arizona?

The historic Canyon Diablo Bridge near Two Guns, Arizona, is a reinforced concrete Luten arch bridge.

The bridge crosses Canyon Diablo about 30 miles east of Flagstaff. Construction began during the winter of 1914–1915, and the bridge opened on March 17, 1915. It later carried automobile traffic on U.S. Route 66 before being replaced by an Interstate 40 crossing.

Its location had long been useful as a crossing point. Travelers first used the Two Guns area by wagon and later by motor vehicle because Canyon Diablo was a difficult obstacle on the route west.

The 146-foot bridge is now abandoned, while the nearby Two Guns site is associated with a former tourist stop and ghost town. It is sometimes confused with other Route 66 bridges in Arizona, including the Red Rock Bridge over the Colorado River, which was a steel cantilever truss structure rather than a concrete arch.