The I. B. Perrine Bridge at Twin Falls, Idaho

Twin Falls, Idaho

Twin Falls is the county seat and largest city of Twin Falls County, Idaho, United States. The population was 44,125 at the 2010 censusTwin Falls is the largest city of Idaho's Magic Valley region...

, United States is a truss arch

Truss arch bridge

A truss arch bridge combines the elements of the truss bridge and the arch bridge. The actual resolution of forces will depend upon the design. If no horizontal thrusting forces are generated this becomes an arch-shaped truss, essentially a bent beam — see moon bridge for an example...

 four-lane bridge carrying U.S. Highway 93

U.S. Route 93 in Idaho

U.S. Route 93 is a north–south U.S. Highway in the U.S. state of Idaho.-Route description:US 93 enters Idaho from a point immediately north of the border casino town of Jackpot, Nevada....

 over the Snake River Canyon

Snake River Canyon (Idaho)

Snake River Canyon is a large canyon formed by the Snake River in the Magic Valley region of southern Idaho. It is well known as the site of an unsuccessful 1974 attempt by Evel Knievel to jump it in the Skycycle X-2....

. Perrine Bridge is approximately 1500 feet (457 m) long and 486 feet (148 m) above the Snake River

Snake River

The Snake is a major river of the greater Pacific Northwest in the United States. At long, it is the largest tributary of the Columbia River, the largest North American river that empties into the Pacific Ocean...

. The bridge serves as the Twin Falls area's main link to Jerome County

Jerome County, Idaho

Jerome County is a county in the U.S. state of Idaho. As of the 2000 Census the county had a population of 18,342 . The county seat and largest city is Jerome....

 and Interstate 84

Interstate 84 in Idaho

In the U.S. state of Idaho, Interstate 84 heads southeast from the Oregon state line, it spurs to Interstate 184 in Boise. Eventually I-84 spurs Interstate 86 and mainline I-84 heads southeast towards Utah and I-86 is continues due east and heads to Pocatello, meeting with Interstate 15.-Future:...

.

Originally named the Twin Falls-Jerome Intercounty Bridge, a steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 cantilever bridge

Cantilever bridge

A cantilever bridge is a bridge built using cantilevers, structures that project horizontally into space, supported on only one end. For small footbridges, the cantilevers may be simple beams; however, large cantilever bridges designed to handle road or rail traffic use trusses built from...

 was opened to traffic in September 1927, and at the time, was the highest bridge in the world.