Colorado is known for things like the old west, the Rocky Mountains, Pikes Peak, cattle farms, being one of the Four Corner states, and for having the highest and longest mountain tunnel! The Eisenhower Tunnel is also the highest point on the interstate across the nation and there’s a lot that goes into maintaining a tunnel this old. Let’s talk a little bit about this tunnel’s rich history, what it takes to keep a tunnel like this running smoothly and finish off with other fun facts about the Centennial state.
William Lovelace is credited for birthing the idea of a tunnel that crossed the Continental Divide as far back as 1867. Instead of creating the tunnel, he created a wagon trail that’s now known as the Loveland Pass. After learning the difficulties that arose nearly a century later, it’s no wonder that the tunnel never came to be any earlier. The tunnel took fifty years of planning, designing and constructing in total, with the Eisenhower Bore started on March 15, 1968 and opening March 8, 1973. This process took so long because fault lines were discovered once boring was initiated. The first contractor was eventually bankrupted after trying to continually excavate rock. The faults began to slip and three workers were killed boring the first tube. (The Eisenhower Tunnel is one of a set of twins; boring the second tube would eventually kill four.) Machinery also struggled to work at a normal pace because of the elevation and the project that was estimated to cost $42 million ended up being $108 million ($741 million in 2024).
It was worth it! This tunnel travels through the Continental Divide at an elevation of 11,155 feet, 1.69 miles in length. In the 70’s, it was the highest in the world and even now, it is the highest in the US. (The tallest is now the Fenghuoshan Tunnel in China.) It’s contract of $54 million was the single largest federal highway contract ever awarded up until that time. In its first four months of being open, it carried its one millionth vehicle, reaching two million just three months later.
Now the Eisenhower Tunnel carries an average of 32k cars daily and is carefully monitored by machinery and a dedicated team to ensure safety. This fifty person team is comprised of trained firefighters and the tunnel even has its own fire truck. A sprinkler system lines the inside of the tunnel in case of fire, as well as 28 600-horsepower fans across the top. The fans work to air out carbon monoxide levels but if a fire were to occur, they would also air out toxic fumes. These are used sparingly though, since the energy cost of just turning them on is $1000. One exhaust fan and one supply fan do operate consistently on low to maintain the carbon monoxide levels. The tunnel also has a height restriction and machinery is stationed outside to monitor vehicle height and the entrance to the tunnel will close, halting all traffic, if a vehicle is too tall. These are all a part of how the Eisenhower Tunnel is monitored and maintained to run smoothly.
Aside from the historical tunnel, Colorado has other notable attributes. For instance, Colorado’s interstate system makes up 10% of the entire state highway system. Most of Colorado’s transportation takes place on the interstate, making it 40% of the 43.5 billion miles of travel. From 2000-2018, interstate travel increased 51% making it the fifth fastest growth in the country. In total, this little state has 956 miles of interstate highway. That’s quite a feat!
Whether you get the chance to experience the Eisenhower Tunnel for yourself or you just find yourself on a stretch of Colorado’s highly traversed interstate system, remember that Interstate Signways has marked the way!
Comments