Eisenhower-Johnson Memorial Tunnels History

Length: 1.7 miles

Cost: $117 million (Eisenhower Tunnel Bore)

Cost: $-145 million (Johnson Tunnel Bore)

Construction Began: 1968 (Eisenhower Tunnel Bore)

Construction Began: 1975 (Johnson Tunnel Bore)

Completion: March 8, 1973 (Eisenhower Tunnel Bore)

Completion: 1979 (Johnson Tunnel Bore)

To alleviate the distance and rigors of travel over U.S. Hwy. 6 at Loveland Pass , the Colorado Department of Highways developed plans for two two-lane tunnels beneath the Continental Divide three miles from Loveland Pass at elevation 11,000 feet.

The Eisenhower Tunnel Bore, today's westbound bore, was the first tunnel completed. It was planned for three years but actually required five years due to unanticipated hazards and the harsh climate. The tunnel bore was 50 feet high and 45 feet wide.

The Eisenhower Memorial Tunnel was dedicated on March 8, 1973. Federal funds had accounted for about 92% of the $108 million cost. At the height of construction, more than 1,140 persons were employed in three shifts, 24 hours a day, six days a week. The prime contractor was actually a consortium of four contractors – Al Johnson Construction Company ( Minneapolis , MN); Gibbons & Reed Company ( Salt Lake City , UT ); Kemper Construction Company ( Los Angeles , CA ); and Western Paving Construction Company ( Denver , CO ).

The Edwin C. Johnson Memorial Tunnel, named for the Colorado legislator, lieutenant governor, governor, and U.S. Senator, required more than 800 workers. Just under 500 of those workers were employed in actual drilling operations. Work began at both the east and west sides; the first hole connecting the two was blasted on August 17, 1978.

Between Eisenhower Tunnel and Silverthorne (7 miles) Construction Completed: 1973

Between Silverthorne and Frisco (5 miles) Construction Began: 1971 Construction Completed: 1972

Between Frisco and Wheeler Junction – Tenmile Canyon – Junction State Highway 91 (6 miles) Construction Began: 1976 Construction Completed: 1979


  • Colorado Constructors, Inc.

POINT OF INTEREST> As part of constructing the interstate through the canyon, a new stream bed had to be built for three of the six miles of Tenmile Creek, from Frisco west. Changing the channel was required since construction would have required frequent stream crossings of the meandering creek. The modification involved several state and federal agencies and Trout Unlimited. The Colorado Division of Wildlife said it was the first time in history that a stream had been re-channelized and the fishing improved. Tenmile Creek is home to at least three varieties of trout: brook, native cutthroat and rainbow.

Between Wheeler Junction and east Vail (15 miles) Construction Began: 1969 Construction Completed: 1978


  • Kiewit Western Company
  • Colorado Constructors, Inc.

POINT OF INTEREST> What route to take? The Vail Pass segment was the subject of much controversy before it was constructed along a route that parallels or shares much of the U.S. 6 route. The Colorado Department of Highways (CDOH) originally proposed to build I-70 west from Silverthorne via the South Willow Creek alignment, through the Eagles Nest Wilderness Area, tunneling under the Gore Range and Red Buffalo Pass, and continuing west via the Gore Creek alignment to Vail (see map). The CDOH dropped the idea after many adversarial public hearings where there was much opposition to going through a wilderness area (see map).

The construction of I-70 over Vail Pass is an excellent illustration of what can be accomplished in an environmentally sensitive area. Innovative construction methods were used to insure maximum preservation of environmental values, including:

  • using bridges instead of fills or cuts to preserve trees and land at several sites
  • making provisions for game crossings
  • designing specialty retaining walls that double as planters to keep right-of-way needs as narrow as possible
  • making irregular rock cuts in natural forms for a more pleasing appearance
  • obliterating haul roads after use and reseeding
  • using settling basins to catch rain and snow runoff from construction to protect water supplies
  • flattening and irregularly shaping slopes to imitate nature
  • placing random rocks in meadow areas and natural rock outcroppings were left in place to give variety to the landscape
  • construction of a bicycle/pedestrian trail, using many segments of the old U.S. 6

Numerous awards have recognized the highway's construction since Vail Pass was truly a monument to working with Mother Nature, not taming her.

Between east Vail and Dowd Junction area - U.S. 6 & 24 (6 miles) Construction Began: 1967 Construction Completed: 1968 Cost: $2,711,132


  • Pioneer Construction Company

Resident Engineer: Vernon Leonard

Project Engineer: Calvin Edwards

Between Dowd Junction area and Avon (4 miles) Construction Completed: 1970 Contractor: Pioneer Construction

Between Avon and Wolcott (10 miles) Construction Completed: 1971

Between Wolcott and Eagle (10 miles) Construction Completed: 1973

Between Eagle and Gypsum (8 miles) Construction Began: 1977 Construction Completed: 1979 Cost: $13.5 million Resident Engineer: Jim Nimon

Between Gypsum and East End of Glenwood Canyon (7.8 miles) Construction Completed: 1980