Eisenhower Tunnel

Eisenhower–Johnson Memorial Tunnel

Eisenhower Tunnel
Overview
Location	Approx. 60 mi (97 km) west of Denver, Colorado
Coordinates	39°40′43″N 105°55′12″W / 39.6785°N 105.92°W / 39.6785; -105.92Coordinates: 39°40′43″N 105°55′12″W / 39.6785°N 105.92°W / 39.6785; -105.92
Route	I-70
Crosses	Continental Divide
Operation
Opened	1973 (westbound) 1979 (eastbound)
Operator	Colorado Department of Transportation
Character	Twin-bore tunnel
Vehicles per day	32,260 vehicles (2007)
Technical
Length	1.693 mi (2.72 km) westbound 1.697 mi (2.73 km) eastbound
Highest elevation	11,158 ft (3,401 m) west portal
Lowest elevation	11,013 ft (3,357 m) east portal
Tunnel clearance	13.92 ft (4.24 m)
Width	40 ft (12.2 m) each
Grade	1.64%

The Eisenhower Tunnel, officially the Eisenhower–Edwin C. Johnson Memorial Tunnel, is a dual-bore, four-lane vehicular tunnel approximately 60 mi (97 km) west of Denver, Colorado, United States. The tunnel carries Interstate 70 under the Continental Divide in the Rocky Mountains. With a maximum elevation of 11,158 ft (3,401 m) 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.

The Eisenhower bore (westbound tunnel) is 1.693 mi (2.72 km) long while the Johnson bore (eastbound tunnel) is 1.697 mi (2.73 km) long. The tunnels are sloped with a 1.64% grade, with an elevation of 11,013 feet (3,357 m) at the east portal and 11,158 ft (3,401 m) 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 48 feet (15 m) by 40 feet (12 m); however, the portion accessible to the public is a square shape measuring just over 16 feet (4.9 m) tall. The rest of the bore is used for forced air ventilation and water drainage systems.