Lordy, lordy, look who’s
40: Eisenhower Tunnel
The world’s highest vehicle tunnel is now 40.
At 11,155 feet in elevation, the Eisenhower bore of the Eisenhower/Johnson Memorial Tunnel provided a lower, faster alternative to the highway Loveland Pass, a two-lane route coifed with hairpin curves that reaches nearly 12,000 feet high.
Located 50 miles west of Denver, the tunnel pierces the Continental Divide and immediately made the nation’s largest ski areas more accessible to a large metropolitan population but also a major international airport. With improved access, the ski areas continued to grow with double-digit gains through the 1970s and into the 1980s.
Dismantling the geography of Colorado was an important precursor for the dominance of the state’s mountain resorts in today’s marketplace. Before the tunnels, California arguably had the better claim as the front-edge of mountain resorts. Squaw Valley hosted the Winter Olympics in 1964, and Mammoth was the busiest ski resort in the country.
But then came the four-lane highway from Denver, the tunnels, and the blossoming of Breckenridge, Vail and other resorts. Sometime during the growth spurt, Vail surpassed Mammoth and hit 1.6 million annual skiers, the benchmark it has hugged for many years, even as Beaver Creek has become a major ski area in its own right.
Such a highway tunnel had been talked about since the 1930s and probably would have happened at some point regardless of federal highway policy and funding. But passage of legislation by the U.S. Congress in 1956 hiked gas taxes and provided 90 percent funding for federal interstate highways.
Construction of the Eisenhower bore began in 1968 and was completed at a cost of $117 million. The Colorado Department of Transportation says today the cost would be $1 billion to $1.5 billion. A second bore, for east-bound traffic, was completed in 1979 at a cost of $145 million.
While the tunnels enabled expansion of the ski areas, the heaviest use occurs during summer. The highest 24-hour traffic count, 50,918 vehicles, was recorded on Aug. 2, 2009. The highest-three-day weekend, 148,300 vehicles, occurred a week later.
But fresh snow can bring out the travelers on weekends, too. The highest one-hour traffic count occurred on March 9, 2007.