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Forty years ago, the Eisenhower and Johnson Memorial tunnels became the state’s transportation linchpin

On Dec. 21, 1979, both tunnels opened to four lanes of traffic and changed how Colorado travels and how the Vail Valley grew

On Dec. 21, 1979, both bores of the Eisenhower/Johnson Memorial Tunnels opened, forever changing traffic flow and economic conditions in the Colorado high country.
Daily file photo
Eisenhower/Johnson Memorial Tunnels facts
  • Traveling through the tunnels the public saves 9.1 miles by not having to travel over U.S. Highway 6, Loveland Pass.
  • The electric bill averages approximately $70,000 per month.
  • The tunnels operate 24-hours a day, seven days a week, employing 52 full-time employees with job duties that range from round-the-clock television surveillance, emergency response, tunnel washing, ventilation maintenance, tunnel sweeping, snow removal, heavy equipment servicing and repair, and water treatment.
  • During construction, approximately 1 million cubic yards of material was cleared from each bore.  190,000 cubic yards of concrete were used for each tunnel lining.
  • There were three fatalities on the first bore; four fatalities on the second bore.
  • The pilot bore was completed in 1964. The Eisenhower Memorial Bore took five years to complete and was dedicated March 8, 1973.  The eastbound Edwin C. Johnson Bore took four years to complete and was dedicated December 21, 1979.

Courtesy of the Colorado Department of Transportation

EAGLE COUNTY — During the busy holiday season, an important Colorado milestone passed.

Dec. 21, 1979, was a historic day for the entire state, and particularly for Colorado’s Western Slope. That’s when the eastbound bore of the Eisenhower and Johnson Memorial Tunnels opened to traffic. The first tunnel had already been in operation for six years but, as noted on the Colorado Department of Transportation website, “The Eisenhower Memorial Tunnel westbound bore hardly had gone into two-way service March 8, 1973, when the need for a second bore under the Continental Divide became evident.”

“When four lanes of Interstate 70 were squeezed to a single lane each direction through the tunnel, the predictable result was a bottleneck impacting summer tourist traffic and wintertime ski rushes, particularly the Denver-bound motorists on Saturday and Sunday evenings,” the CDOT website continues.



Today, it’s hard to imagine what it would be like to navigate Interstate 70 through the Colorado High Country without the tunnel in service. According to CDOT, more than 13 million vehicles — an average that hovers around approximately 40,000 vehicles per day — travel through the tunnels each year.

“When you look at today’s traffic, I don’t know what we would do without the tunnels,” said Kent Rose, who moved to Vail back in 1972 to take the job as the town’s engineer. “If we were down to two lanes now, with the traffic we have, it could take a week to get down to Denver.”

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Two-hour rule

The legacy of the Eisenhower and Johnson Memorial Tunnels is very personal for Merv Lapin of Vail. He staked his financial future on the project.

“It was one of the things that kept me in Vail,” Lapin said. “It made me realize that the trip to Denver would only take an hour and a half or two hours. I knew the tunnel project would make Vail more popular. It was one of the elements that told me there was a potential business for me.”

In his case, that business involved accumulating land and doing land partnerships for properties in the path of development. For Lapin, I-70 defined that path.

By the numbers, the Eisenhower and Johnson tunnels cut 9.1 miles from the trip to and from Denver. But that number doesn’t really measure the impact. Before the twin tunnels opened, motorists had to travel two-lane Loveland Pass to cross the Continental Divide.

“It used to take four hours to get to Vail. When you lived here, you would make a trip every two to four weeks to go to Denver to get what you needed to buy,” Lapin said.

Cutting two hours off the trip time was a game-changer in both directions. For Vail, it meant more people could reasonably access its famed slopes. As motorists know, there are two major I-70 features that pave the way to Eagle County. Vail Pass dates back to the 1940s and the roadway was upgraded to four-lane I-70 in 1978. But it wasn’t until the twin tunnels opened that all the pieces were in place to easily get to the resort town.

“On the East Coast, the rule of thumb is for a ski area to make it, it has to be located within two hours of a major metropolitan area,” Lapin said. “Everyone around Vail was very supportive of it (the tunnel construction). The town of Vail looked at it as a project that would cause more people to come to Vail.”

Corridor linchpin

Eventually, completion of the Eisenhower and Johnson Memorial Tunnels meant that more Denver-area dwellers invested in second homes in the Vail Valley because they could more easily visit the area, Lapin said.

“It also became a lot easier and cheaper to get goods delivered here. It became a more competitive market.”

Forty years later, CDOT officials note that the twin tunnels remain a vital part of Colorado transportation and commerce.

“The Eisenhower-Johnson Memorial Tunnels is a critical facility since the I-70 Corridor is the primary east/west highway in Colorado,” said Patrick Chavez, the coordinator of CDOT’s Statewide Traffic Incident Management Program. “We see that when there is a closure anywhere on the corridor with alternate routes quickly becoming congested from the volumes being diverted from I-70.”

He said the twin tunnels are key to the management of highway operations and the linchpin of the corridor. 

“What happens at the Eisenhower/Johnson Memorial Tunnels has huge impacts from Golden to Vail and the enormous volumes of traffic that flow through that area,” Chavez said. “The I-70 Corridor is one of the main drivers of economic benefit for Colorado that supports both internal/external state commerce but also internal and out-of-state recreation travel. Because the Eisenhower/Johnson Memorial Tunnels is at the center of this corridor, it makes it extremely critical to the overall effective operations of the corridor.”

As technology has advanced, the twin tunnels have become even more important to the state.

“The Eisenhower-Johnson Memorial Tunnels provides the infrastructure for fiber optic communications and we are also working on a project to provide better cell service coverage throughout the tunnel with antennas,” said CDOT Region 1 Tunnel Resident Engineer Neal Retzer.

The twin tunnels also serve the I-70 corridor as a dispatch/operations center from Dotsero to Golden.

“We also respond to emergencies in the area since we have several response vehicles like firetrucks and employees with EMT training,” Retzer said. “We have our own domestic water supply and treatment facilities. We also house several types of avalanche management supplies and provide support for those operations in the area such as the west side of the continental divide and along US 6 over Loveland Pass.”

According to the CDOT website, the total cost of the project was $108 million. In today’s dollars, that sounds like a deal, considering the Grand Avenue Bridge replacement project in Glenwood Springs it cost $125.6 million. But the tunnel construction was a monumental financial and engineering challenge.

During the height of construction of the Eisenhower bore, as many as 1,140 construction workers were employed in three shifts, 24 hours a day, six days a week. More than 800 workers built the Johnson bore, some 480 of them in actual drilling operations. Today, 40 years after they became fully operational, the structures are more vital than ever.

“Construction of both tunnels has attracted international attention; engineers and rock mechanics from free world and communist countries alike have toured the site 60 miles west of Denver,” notes the CDOT website. “The technical aspects will continue to fascinate engineering professionals.  But for hundreds of thousands of highway users, the tunnels will continue to save 30 minutes to an hour in drive time compared to U.S. 6 over Loveland Pass. After 12 years of construction time, the task that seemed impossible to some persons and improbable to many others had been accomplished.”


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