Mike O’Callaghan—Pat Tillman Memorial Bridge
Temperatures upward of 115°F, winds capable of felling cranes, an 890-foot drop below: “Inhospitable” doesn’t begin to describe conditions at the Colorado River’s new Mike O’Callaghan–Pat Tillman Memorial Bridge.
A 1,900-foot span designed to divert traffic from the narrow, switchback-laden road across the Hoover Dam, it will be the longest concrete arch bridge in the Western Hemisphere when it opens next fall, with 106 segments of ultra-high-strength concrete forming a twin-rib arch. Workers scaled the canyon’s walls, digging notches for concrete foundation columns. To construct the 1,060-foot-long arch, they cast 24 feet of concrete at a time, while a separate, temporary cable-stayed bridge held up the unfinished ends until the gap was closed this year.
