Hanging Lake

The Hanging Lake Viaduct completes the final phase and 10 years of construction through the canyons of Colorado. The completion of Interstate 70 through this spectacular canyon is true evidence of our human ability to blend the marvels of engineering with the wonders of nature.

Construction of this concrete segmental structure was awarded to Flatiron/Prescon Joint Venture based on a bid of $34.1 million. (The low steel bid was $35.2 million.)

The crossing of the Colorado River consists of dual 300-ft. spans. Segments are 33-ft.-6-in. wide and taper from a depth of 12-ft.-6-in. at the pier to 10 ft. at mid-span. The viaduct portion of the structure consists of nominal 200-ft. spans with 10-ft. deep segments, having 1,156 segments in 42 spans. Segment weights range from 40 to 55 tons.

In order to build in the narrow canyon without disturbing traffic and the environment, an overhead launching gantry was used. This gantry allowed construction to be completed entirely from above. The unique gantry was capable of placing segments in a curved span and the viaduct was built using the balanced-cantilever erection method.

Construction of the Hanging Lake Viaduct began in December of 1989 and was completed in September 1992.