The Winding Road Through Glenwood Canyon Showcases the Marvels of America's Interstate System

The 12.5-mile stretch of I-70 through Colorado's Glenwood Canyon is an engineering marvel, taking 12 years and $490 million to complete.

Published on Feb. 10, 2026

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The story explores the history and significance of the U.S. Interstate Highway System, focusing on the challenging construction of the 12.5-mile stretch of Interstate 70 through Colorado's Glenwood Canyon. Completed in 1992, this portion of I-70 was one of the most difficult sections to build, requiring the creation of tunnels, bridges, and viaducts to navigate the dramatic natural landscape. The article highlights how the interstate system has transformed America, enabling increased mobility, commerce, and exploration, while also serving as a playground for car enthusiasts.

Why it matters

The Interstate Highway System is a marvel of American engineering and a critical piece of infrastructure that has profoundly shaped the country's development and way of life. The Glenwood Canyon section of I-70 exemplifies the system's ability to overcome daunting geographical obstacles, integrating seamlessly with the natural landscape. This story underscores the interstate's enduring importance, even as technology continues to advance vehicle capabilities.

The details

To build the 12.5-mile stretch of I-70 through Glenwood Canyon, workers bored three tunnels, constructed about 40 bridges and viaducts, installed 15 miles of retaining walls, and used 30 million pounds of structural steel, 30 million pounds of reinforcing steel, and over 800,000 tons of concrete. The highway is held up on 90-foot piers over the Colorado River's whitewater at certain points. The project took 12 years to complete, nearly 12 times as long as it took to build the Empire State Building, and cost $490 million (about $1.15 billion today).

  • The Glenwood Canyon section of I-70 opened on October 14, 1992, which happens to be Dwight D. Eisenhower's birthday.
  • Construction on the Glenwood Canyon project began in 1980 and was completed in 1992.

The players

Dwight D. Eisenhower

The 34th President of the United States, who was instrumental in the creation of the U.S. Interstate Highway System after experiencing the challenges of cross-country travel during a 1919 Army convoy trip.

Frank Turner

The former head of the Federal Highway Administration, who stated that the interstate system "will never be finished because America will never be finished."

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What’s next

The Interstate Highway System continues to evolve, with numerous federal highway projects currently in the works to expand and modernize the network.

The takeaway

The Glenwood Canyon section of I-70 stands as a testament to the ambition, engineering prowess, and transformative impact of the U.S. Interstate Highway System, which has profoundly shaped the country's development, economy, and way of life over the past seven decades.