Officials prepare for probable Glenwood Canyon closures again this summer; detour plans use Silverthorne to bypass I-70

Jason Auslander
Aspen Times
Colorado Department of Transportation trucks wait to be filled up with rock and mud in Glenwood Canyon during a cleanup in August 2021.
Chris Dillmann / Vail Daily

State and local emergency management officials met this week on the Western Slope to cement plans for the likely event that Glenwood Canyon and Interstate 70 close again this summer because of mudslides, rockfall or other reasons.

Two tabletop exercises took place Tuesday in Glenwood Springs and Wednesday in Gunnison to execute plans for what will happen in Pitkin County, the Aspen area and Independence Pass if the canyon closes, said Elise Thatcher, Colorado Department of Transportation spokeswoman.

“Our team has really been going the extra mile to make sure we’re protecting the canyon as much as possible,” Thatcher said Thursday. “It’s April, and we’ve been working since August (to clear debris).”

Glenwood Canyon closed frequently last summer after monsoons brought down mudslides and large rocks on to I-70, which occurred because of the Grizzly Creek Fire in the canyon in the summer of 2020.

The plan this summer will be similar to last summer, when flash flood watches caused CDOT to close rest and recreation areas in Glenwood Canyon, and flash flood warnings meant I-70 and the canyon were shut down to through traffic in both directions, Thatcher said.

When that happens this year, westbound traffic from Denver again will again be routed north on Colorado Highway 9 from Silverthorne to U.S. Highway 40 through Steamboat Springs to Craig, then back down Colorado Highway 13 to Rifle on I-70. Eastbound traffic will follow the opposite route.

A southern route is less optimal because major construction on U.S. Highway 50 between Montrose and Gunnison will continue this summer. In the event of extended canyon closures, however, that work can be stopped temporarily if it’s necessary to deal with traffic volumes, Thatcher said.

Eastbound drivers headed for the Roaring Fork Valley will be allowed to continue on I-70 to Glenwood Springs and Highway 82, and westbound drivers will be able to continue past Silverthorne to Highway 91 at Copper Mountain through Leadville to Highway 82, she said. Westbound drivers who need to reach points west of Silverthorne will be allowed to go as far as Gypsum.

A Colorado Department of Transportation employee and Pitkin County Sheriff's deputy talk with truck drivers in late July at the Independence Pass gate east of Aspen. Semitrucks and vehicles longer than 35 feet are not allowed on Highway 82 over the Pass. These three truckers had to turn around and were not fined. (David Krause / The Aspen Times)

“While we hope I-70 will not be impacted by debris flows this summer, businesses and residents should be prepared for this possibility and sign up for emergency alerts at,” Glenwood Springs City Manager Debra Figueroa said.

Law enforcement and CDOT employees will be posted at winter closure gates on the Pitkin County and Lake County sides of Independence Pass on the look out for vehicles longer than 35 feet, which are not allowed on the narrow road. Thatcher emphasized that any vehicle longer than a total of 35 feet — not just semi-trucks but also recreational vehicles and trucks pulling trailers — are included in the prohibited category.

“If you are over 35 feet, you will face a fine if you’re caught,” she said. “And if you cause traffic problems, the fine gets bigger.”

Pitkin County Undersheriff Alex Burchetta, who participated in Tuesday’s meeting in Glenwood Springs, also reiterated that point.

“It’s not a prohibition on commercial vehicles,” Burchetta said. “It’s all vehicles over 35 feet. If you’re towing a Jeep with a big truck (that counts). It’s any vehicle with a combined length over 35 feet.”

While the emphasis might seem like overkill, it’s not.

Vehicles were stuck at a standstill on Independence Pass due to a disabled vehicle between mile markers 47 and 51 in early August.
Samantha Johnston/The Aspen Times

The frequent Glenwood Canyon closures last year funneled numerous semi-trucks and tourists towing over-length recreational toys through Aspen in an attempt to climb over the Pass. The incidents occurred despite numerous large signs on Highway 82 from Glenwood to Aspen and on the Lake County side warning of the 35-foot maximum.

Burchetta said the Pitkin County Sheriff’s Office will be notified immediately by CDOT personnel in Glenwood Canyon when a closure occurs this summer. At that point, his office will send a deputy to an area east of Aspen to make sure oversized vehicles do not make it through.

The plan is for CDOT employees to come relieve Pitkin County deputies within an hour, he said.

“I think we would be remiss if we didn’t plan for (canyon closures) and consider it a possibility,” Burchetta said. “CDOT has put a tremendous amount of effort into this plan and they have made it a seamless and effective plan.”

Significant problems on the Independence Pass road are caused by the two sections of road just above Aspen when it narrows to one lane. Inexperienced mountain drivers do not handle those sections well, while over-length vehicles that slip through can easily clog the road and cause major issues that law enforcement have a hard time reaching to untangle.

CDOT installed portable traffic lights at each end of the two sections last year that worked well in controlling the flow and easing driver anxiety, Thatcher said. Those lights will be put up again this year when the canyon closes and may be operative during non-closure times, as well.

This story is from Glenwood Springs Post Independent reporter Ike Fredregill contributed to this story.

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