5 things to know on the 50th anniversary of construction starting on the Eisenhower-Johnson Memorial Tunnels

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Hart Van Denburg/CPR News
A view of the west entrance to the Eisenhower Tunnel on Interstate 70 on Wednesday, Nov. 11, 2020.

It’s been 50 years since a blast of dynamite signaled the start of the Straight Creek Tunnel, a project that would later become a vital corridor through the Rockies known as the Eisenhower-Johnson Memorial Tunnels. 

In 1968, the project was a massive undertaking and resulted in the highest point on the US Interstate system, sitting at an elevation of more than 11,000 feet.

Lisa Schoch, a senior historian at the Colorado Department of Transportation, spoke to Colorado Matters about the tunnel’s history.

Five Things To Know About Tunnels

  1. Without the tunnels, the country’s Interstate system would not have gone through Western Colorado and would have abruptly stopped in Denver.
  2. Only one woman worked inside the tunnel during construction. Janet Bonnema, a University of Colorado grad, was hired by Colorado Department of Transportation officials who thought she was a man. When they discovered she was a woman, they almost didn’t let her work. But Bonnema filed a sexual discrimination lawsuit against the state and got the job. 
  3. There’s a lot going on above drivers’ heads in the tunnel. Along with a fully staffed control center, there’s a ventilation system large enough to ride a bike through.
  4. Seven men died during the tunnel's construction but there have been no motorist fatalities since.
  5. The Johnson bore of the tunnel is not named after President Lyndon Johnson. It’s actually named after a former governor of Colorado, Edwin Johnson.