One of Colorado’s most iconic man-made structures is easily the Eisenhower-Johnson Memorial Tunnel. Connecting Clear Creek County on the East and Summit County on the West, the tunnel is a vital transportation route for recreation, travel, shipping, and much more. But it wasn’t a completed project until 1979, and before then, travelers were forced to move over sketchy passes like Berthoud and Loveland. It’s construction has been huge for Colorado, but it wasn’t easy.
Construction on the Eisenhower-Johnson Memorial Tunnel ran between 1968 and 1979, forcing crews to battle unstable fault zones, extreme weather, and thin air. The project required innovative tunneling methods to create a four-lane, year-round interstate tunnel route.
Today the tunnels carry tens of thousands of vehicles every single day, requiring constant maintenance on the massive ventilation systems and continuous avalanche mitigation in the winter. But they’ve eased travel, linked isolated communities, and supported tourism. Without them, Colorado and it’s outdoor recreation, including the ski industry, would be very different.
