Due to the extreme avalanche conditions and large amounts of snowfall in early March, Red Mountain Pass, the 20 mile stretch of Highway 550 connecting Silverton to Ouray, has been closed since March 3rd and is now open as of Friday March 22nd.

With the high snowfall in Southern Colorado throughout the month of March, Red Mountain Pass, poses a different set of hazards for travelers on Highway 550, with the added danger of large avalanches that can cover the road in many places, said Lisa Schwantes, Southwest Regional Communications Manager for CDOT.

 This map at the CDOT Southwest Regional Headquarters show all of the different avalanche paths that cross over Highway 550 in the Red Mountain Pass Stretch. All orange spots are known slide paths. Photo by Nate DeCremer

On March 3, at 11:00 p.m, Indicator slides, small avalanches that indicate potential for larger avalanches to follow, started to cover the road, but were small enough that the plow can still move the snow out of the way, said Schwantes.

“At about eleven o’clock that night after visiting with the Colorado Avalanche Information Center, it was determined that evening that we were going to close that pass,” says Schwantes.

The following morning CDOT maintenance crew started performing avalanche mitigation, a common practice where crews will purposefully trigger avalanches using explosives, so that they don’t slide unexpectedly, which could trap and kill road crews and commuters traveling over the pass, said Schwantes.

“One of the largest slide paths with the potential of falling on the highway, ran after being mitigated, and it came down like no one has ever seen before,” said Schwantes. “They are estimating, I think it was 20-30 feet deep, and what they call dirty. That means that there was rocks, limbs, entire trees that came down for about a half a mile.”

The North side of the pass had an equal amount of coverage by avalanches. The roadway was covered by avalanches from both sides of the canyon covering the highway under 30-40 feet of snow and debris, said Schwantes.

The pass was closed since those incidents and continued to remain closed due to the snowstorms which produced extreme avalanche danger, making it unsafe for CDOT crews to perform maintenance on the Red Mountain Pass, said Schwantes.

After the final storm that happened on the 15th of March, crews were finally able to start clearing the roadway, nonstop 24 hours a day in 12 hour shifts, to clear snow and debris, ranging anywhere from three to 60 feet in depth for the 20 miles of U.S 550 said Schwantes.

With the CDOT crews extensive avalanche mitigation and roadwork, they were able to safely open Red Mountain Pass from Silverton to Ouray on Friday March 22nd.