Red Mountain Pass closed for about 24 hours Sunday and Monday after a rockslide buried U.S. Highway 550 in 4 feet to 10 feet of rock and mud on Sunday.
Motorists will encounter one-lane, alternating traffic controlled by portable traffic signals while crews continue cleanup efforts and assess structural damage to the highway, said Lisa Schwantes, spokeswoman for the Colorado Department of Transportation.
The highway was closed from about 5 p.m. Sunday to 5 p.m. Monday for a rockslide about 2 miles south of Ouray, according to the Colorado Department of Transportation. But multiple stretches of the highway experienced flooding and debris flows.
"To ensure the safety of the traveling public and our maintenance crews while they operated heavy equipment, the highway was closed through the night and today (Monday) for clearing and damage assessment," said John Palmer, CDOT deputy superintendent of maintenance, in a news release.
Crews also assessed possible damage to the roadway and structures.
"Our team paid particular attention to a cribwall, which was in the path of one of the more significant rock slides," said Kevin Curry, CDOT program engineer. "Cribwalls are essentially retaining structures which stabilize the road surface. They are designed to support highways which have steep drop-offs."
Geotechnical staff from CDOT's Denver headquarters were en route Monday to Red Mountain Pass to further assess road and structure damage, as well as the stability of the cliffs and mountainsides immediately above the highway.
"As our teams move forward assessing damage and planning for required repairs, we will be diligent in working with both San Juan and Ouray counties and the communities along this busy corridor to establish a plan for how we will manage traffic through this operation," said Mike McVaugh, CDOT's southwest regional transportation director.
The rockslide was the result of heavy rain in the high country.
"We have not had any moisture, so when we suddenly get a downpour, that water doesn't necessarily soak into the ground like it should," Schwantes said. "... It looks like this came from way up high."