photo from inside Eisenhower Tunnel under construction

Colorful Colorado

Putting a Five-Story Building Through a Mountain: How a Tunnel Transformed Colorado

Located near the geographic center of Colorado, the Eisenhower-Johnson Memorial Tunnels extend 1.7 miles beneath the Continental Divide. Cars disappear into one portal and emerge in less than five minutes—and their drivers are more likely to notice vastly different weather conditions on the other side than to think about the political, financial, engineering, and muscle power that made the tunnels happen. Planning and construction spanned four decades starting in the 1930s, when the State Highway Department was barely into its second decade and the country was in the midst of a Great Depression. When the first of the tunnels—originally called Straight Creek—opened in 1973, it marked a turning point for the highway department and helped shape Colorado’s identity as a western state. See historic images from the CDOT photo collection as you take a trip through the growth of Colorado’s early road system, the state highway department, and our interstate highways.

View from inside Eisenhower tunnel