Can Cottonwood Pass ever be a viable detour when I-70 though Glenwood Canyon is closed?
December 4, 2016
GYPSUM — A short story tucked in at the bottom of the Nov. 27, 1936, edition of the Eagle Valley Enterprise raises a question that is 80 years old and still bears asking.
Can Cottonwood Pass ever really be a serviceable detour when traffic is closed down in Glenwood Canyon?
Eighty years ago, just like today, the answer is "not really."
"The road over Cottonwood is not much pumpkins," stated the Enterprise back in '36. "The improvement not being such as will permit heavy traffic to any extent. Buses and big trucks are going to have a hard time when compelled to use the road."
Those words played out last winter when Interstate 70 through the canyon was closed for six days straight after a massive rockfall. Traffic was re-routed via U.S. Highway 40 to the north of U.S. Highway 50 to the south — detours that added hours to driving time and kept area residents from reaching jobs on the other side of the canyon. Motorists who tried to drive Cottonwood Pass in winter conditions quickly realized the folly of their actions.
"Another week-long closure at Glenwood Canyon is not an if, it's a when," said Gypsum Town Manager Jeff Shroll. "At a minimum, Cottonwood Pass should be a two lane, paved, year-around road."
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Instead, the route that starts south of Gypsum and ends at Colorado State Highway 82 in the Roaring Fork Valley is partially paved, partially dirt and features one exceptionally steep, curvy section that is difficult to navigate in bad weather with a four-wheel drive vehicle, let alone a tractor-trailer.
Canyon versus Cottonwood
The Glenwood Canyon I-70 route decision was made more than 30 years ago. In her book "A Guide to Glenwood Canyon," author Heather McGregor writes "In 1958, federal officials mapped Interstate 70 across Colorado as part of a new network of high-speed, four-lane, limited-access highways. But not until 1975 did they officially put the route though Glenwood Canyon."
McGregor noted that routes across the Flat Tops and Cottonwood Pass were rejected at that time.
That decision proved to be controversial as a cadre of locals, including singer John Denver, decried the environmental impact I-70 would exact.
"Weighed against those issues were safety concerns. The rate of fatal auto accidents in Glenwood Canyon was from two to 12 times higher than other highways in western Colorado and traffic was bound to increase," wrote McGregor.
As for the Cottonwood Pass idea, the chief arguments against the route were length and cost. The Glenwood Canyon route covered 27.5 miles, the Cottonwood Pass route covered 36.7 miles
The Environmental Impact Statement for the I-70 expansion from Gypsum to Glenwood Springs completed in 1972 considered various routes for the segment and identified Glenwood Canyon and Cottonwood Pass at the two main alternatives. After completion of the study, the Colorado Department of Highways concluded Glenwood Canyon was the most suitable route for build I-70.
Investigation of the two routes concluded that the Glenwood Canyon route did not contain any areas where geologic conditions would prevent roadway location and few areas of unfavorable geologic conditions. The report stated that the Cottonwood Pass route contained existing and potential landslides which were considered to be the most significant adverse effect. Other factors include the unstable and highly erodible materials encountered along this route. Those conditions were part of the reason the 1972 estimated cost for the Cottonwood Pass route was significantly higher — $440 million compared to the canyon's construction estimate of $367 million.
Beyond the conditions and costs, the viability of the Cottonwood Pass route was also questioned. At that time, there was a two-lane road through the canyon and there was a strong argument that traffic would simply continue to use the shorter canyon route if I-70 was routed over Cottonwood Pass.
The Glenwood Canyon section of I-70 officially opened on Oct. 14, 1992, linking the eastern and western sections of the country. But the highway also had an immediate and significant impact for Eagle County and Garfield County residents.
With I-70 open, it became practical for residents to commute to jobs on either side of the canyon. So today, when the highway closes down, it has a significant impact on neighboring communities.
Last winter's six-day I-70 closure was "devastating" for Glenwood Springs, said acting city manager Andrew Gorgey. "It really showed us how huge a lifeline that is for our economy, which depends on that interstate traffic," said Gorgey in an interview with the Glenwood Post Independent.
Last June, a group of county and municipal government officials gathered to discuss the viability of making Cottonwood Pass a viable detour — the issue that the Enterprise raised 80 years ago.
Their conclusion was it will take a lot of teamwork and money to shape Cottonwood Pass into anything more than a primitive, seasonal road. Even a partial gravel surface with 11-foot travel lanes and four-foot shoulder that could be maintained through the winter would be costly.
Eagle County conducted preliminary analysis of just such an upgrade in 2010 and came up with a cost of $48 million to do the work. A wider surface with 12-foot lanes and six-foot shoulders would have cost about $66 million. What's more, during that June session Eagle County Engineer Eva Wilson said those cost estimates are probably on the low end.
Following the June confab, the state said it would gauge interest among area governments to do a feasibility study for a Cottonwood Pass detour. Such a study would cost in the neighborhood of $300,000.
Meanwhile, communities on the east and west ends of the canyon head into the winter months hoping that closures will be kept to a minimum.
"You close that canyon and we can see it," said Shroll. "When the canyon is open, we love it. You don't think about it until you want to get to the hot springs and you can't get there."