Eisenhower-Tunnel

The Eisenhower Tunnel, officially the Eisenhower–Edwin C. Johnson Memorial Tunnel, is a dual-bore, four-lane vehicular tunnel approximately 60mi west of Denver, Colorado, United States. The tunnel carries Interstate 70 under the Continental Divide in the Rocky Mountains. With a maximum elevation of 11158ft AMSL, it is one of the highest vehicular tunnels in the world. The tunnel is the longest mountain tunnel and highest point on the Interstate Highway System. Completed in 1979, it was one of the last major pieces of the Interstate Highway system to be completed. The westbound bore is named after Dwight D. Eisenhower, the U.S. President for whom the Interstate system is also named. The eastbound bore is named for Edwin C. Johnson, a governor and U.S. Senator who lobbied for an Interstate Highway to be built across Colorado.DescriptionThe Eisenhower bore (westbound tunnel) is 1.693mi long while the Johnson bore (eastbound tunnel) is 1.697mi long. The tunnels are sloped with a 1.64% grade, with an elevation of at the east portal and 11158ft at the west portal. At the time of dedication, they were the highest vehicular tunnels in the world. While the Eisenhower Tunnel remains the highest vehicular tunnel in the United States, higher tunnels have since been constructed elsewhere, such as the Fenghuoshan Tunnel, a rail tunnel in China. The Eisenhower tunnel is noted as the longest mountain tunnel and highest point on the Interstate Highway System. The tunnel bores measure 48ft by 40ft; however, the portion accessible to the public is a square shape measuring just over 16ft tall. The rest of the bore is used for forced air ventilation and water drainage systems.