UPDATE, 3:38 p.m.

U.S. Highway 550 over Red Mountain Pass will remain closed the rest of the night, as adverse weather conditions have made avalanche mitigation operations impossible to perform, according to the Colorado Department of Transportation.

High accumulations of snow, high winds, blowing snow and low visibility have forced maintenance personnel to leave the pass. Crews have reported more than 18 inches of new snow in the past few hours.

Southbound traffic will be stopped just south of Our...