Prolonged Glenwood Canyon closure tests the limits of Cottonwood Pass

The old mountain road is providing important access for residents and workers but it is not an advised I-70 detour

A steady stream of traffic makes its way over Cottonwood Pass between Glenwood Springs and Gyspum due to the Interstate 70 closure in Glenwood Canyon.
Chelsea Self/Post Independent

As the latest Glenwood Canyon Interstate 70 closure enters its second week, it’s the question that locals find themselves asking daily: What about Cottonwood Pass?

That single question actually reflects a number of specific queries. Is Cottonwood open? Is it passable for standard passenger vehicles? Can a trailer be hauled over the pass? Are there restrictions in place?

But the most important question underlies all those concerns: Is Cottonwood Pass safe? The answer is an unsatisfying “it depends.”

For residents familiar with primitive, mountain roads who need to get to work or important appointments, Cottonwood Pass has become a lifeline. But that doesn’t mean it’s an advised I-70 detour route.

A steady stream of traffic makes its way over Cottonwood Pass between Glenwood Springs and Gypsum due to the I-70 closure in Glenwood Canyon.
Chelsea Self/Post Independent

“It is not a safe road for that much use,” said Eagle County Manager Jeff Shroll. “For the most part, we tell people not to use it unless it is absolutely necessary. GPS apps are no longer directing people there, and we certainly don’t want them to.”

But the extended canyon closure has inevitably brought more traffic to Cottonwood Pass and renewed the debate about what it would take to make the route a viable detour for I-70. It isn’t, as a recent Denver television station report suggested, a “secret” alternative to the CDOT advised detour for I-70. It’s a rough, unpaved back road bridging two counties, and that reality has required Eagle County’s increased supervision as more motorists attempt to traverse it.

Vehicles line up at the Blue Hill/The Narrows section of Cottonwood Pass on Friday. Eagle County personnel direct one-way traffic along that section of road.
Pam Boyd/

Through the narrows

Mudslides in the Grizzly Creek Fire scar area have occurred throughout this summer, but the most recent slide-caused closure July 29 caused considerable damage to I-70 and resulted in Gov. Jared Polis issuing a statement noting that the interstate will likely remain closed for weeks.

Confronted by that reality, Shroll said Eagle County had no choice but to place personnel at both ends of the pass to turn away oversize vehicles. There are lines on the pre-pass pavement, and vehicles that exceed size limits are turned around. After motorists embark on Cottonwood Pass itself, they encounter more county personnel at the Blue Hill/Narrows area. Crews there regulate one-day traffic at the particularly treacherous section.

Rocks and debris pile multiple feet high Friday in a drainage in Glenwood Canyon near Bair Ranch. Interstate 70 through the canyon has been shut down since July 29.
Chelsea Self/Post Independent

“We have to do it. It is a safety issue. There is too much traffic on Cottonwood Pass to let that section go by itself,” Shroll said.

So far, county personnel have spent more than 1,200 hours manning the Cottonwood Pass checkpoints, Shroll said. “They get there at 6 in the morning and people have been out there until as late as midnight.”

Shroll got a firsthand education about what county employees face at Cottonwood Pass when he manned one of the checkpoints last week.

“It was eye-opening, learning how many people need it for traveling,” he said. “There is just a lot of people who work in both valleys and travel back and forth. They couldn’t do their jobs if that pass didn’t exist.”

Shroll noted those commuters include law enforcement officers, health care workers and other essential personnel. As the school year approaches, teachers will also depend on Cottonwood Pass to get to work if the canyon remains closed, he said.

“It’s just going to get more use,” Shroll noted, “and the rain that closed I-70 wasn’t kind on Cottonwood Pass, either, last week.”

Leaders in both Eagle and Garfield counties readily agree the road needs work to make it safer — not as a full-scale detour but as a passable alternative for locals who need the access. But there are no easy fixes for this problem.

For 85 years, valley residents have asked if Cottonwood Pass could be a reliable alternative to Glenwood Canyon as demonstrated by this Nov. 26, 1937, story in the Eagle Valley Enterprise.
Daily file photo

The route not chosen

A short story tucked in at the bottom of the Nov. 27, 1936, edition of the Eagle Valley Enterprise also asked an 85-year-old question: Can Cottonwood Pass ever really be a serviceable detour when traffic is closed down in Glenwood Canyon?

“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 could have been written this week after the latest extended closure.

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.”

Traffic is thick Wednesday on Cottonwood Pass between Garfield and Eagle counties.
John Stroud/Post Independent

McGregor noted that routes across the Flat Tops and Cottonwood Pass were rejected at that time.

The decision to build an interstate highway though this part of the Colorado High Country 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 as the two main alternatives. After completion of the study, the Colorado Department of Highways concluded Glenwood Canyon was the most suitable route for building 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 included the unstable and highly erodible materials encountered along the route. Those conditions were part of the reason the 1972 estimated cost for the Cottonwood Pass route was significantly higher — $440 million compared with 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.

Raven Duty from Eagle County Public Works directs a motorist toward Cottonwood Pass. The county has been stationing personnel at both ends of the pass and at the Blue Hill/Narrows sections to improve safety on the primitive mountain road.
Pam Boyd/

Tuesday talks

The Eagle County Board of Commissioners agenda on Tuesday, Aug. 10, features an afternoon devoted to the Cottonwood Pass dilemma. First, the Eagle County officials will discuss potential improvements among themselves. Then, later in the afternoon, they will trek over to Garfield County — via Cottonwood Pass — to discuss the issue with their Garfield County counterparts.

Shroll said potential improvements include widening some of the narrower corners along the pass and increasing road maintenance. “Our current goal is to keep it safe as it is,” he noted.

“Some of this is just out of our control,” Shroll continued. “It’s just not something that Eagle and Garfield counties can decide or spend the millions and millions of dollars it will take to make improvements. That decision has to be made with the state and the federal government.”

Back in 2010, Eagle County conducted preliminary analysis for Cottonwood Pass improvements. That study estimated a $48 million price tag for basic improvements. A project that included a wider surface with 12-foot lanes and 6-foot shoulders was estimated at $66 million. But 11 years have since passed, and those estimates would be considerably higher today.

While discussion about long-term impacts of I-70 canyon closures has started, it obviously won’t bring relief in the short term as Colorado Department of Transportation crews continue hauling debris from the canyon and assessing road damage in the area.

For now, Cottonwood Pass remains a limited scope alternative, but it will remain so only if a manageable number of vehicles use the route.

“We ask people to check the CDOT travel advisories and plan accordingly,” Shroll said. “Have patience, and don’t take out frustrations on the people up there doing their jobs.”

From his experience on the pass, Shroll said most motorists are grateful to have county crews managing traffic along the scarier sections.

“I got lots of thank-yous and only a couple of middle fingers,” he said. “The crews are doing a great job.”

Motorist appreciation often comes in physical form, he added.

“People offer our workers water and sodas. I even had a guy offer me a peanut butter and jelly sandwich,” he said.