A avalanche about 10 miles north of Silverton closed U.S. Highway 550 at mile marker 80. The road has since reopened.
Lisa Schwantes, spokeswoman with the Colorado Department of Transportation, said the natural slide occurred early Sunday afternoon, and a crew is working to clear about a 50-foot stretch of highway covered with 3 to 5 feet of snow.
The Colorado Avalanche Information Center lists the risk of avalanches in the San Juan Mountains at considerable, or a 3 on a 5-point scale. A 5 is considered extreme avalanche danger.
Schwantes said high winds combined with the amount of snow from the last few storms have increased the probability of slides.
CDOT also scheduled the retrieval of a semitrailer that had slid off U.S. Highway 160 east of Bayfield for Sunday morning.
Schwantes said crews got a late start and removal of the vehicle was completed around 2:50 p.m. Sunday.
Traffic was narrowed to one-lane, alternating traffic at times during the retrieval, but the highway was never fully closed as a crew removed the semitrailer.