Red Mountain Pass will remain closed “at least through the weekend” while road crews work to mitigate a rockslide south of Ouray, the Colorado Department of Transportation announced Tuesday.
“There is currently no estimate for reopening of the pass beyond this weekend, though more will be known by Friday as mitigation work gets underway,” the agency said Tuesday night in a news release.
The slide was first reported about 7:30 p.m. Sunday, closing the pass for about two hours while crews removed debris. But more rubble came down about 12:40 p.m. Monday, which has closed the pass ever since.
Loose rocks continue to trickle down sporadically, creating traffic hazards for motorists, said Nancy Shanks, spokeswoman for CDOT.
Two drivers reported broken windshields and at least one driver experienced a flat tire after the pass opened for a brief time Monday, she said.
“The risk is too great, and the risk is unknown,” Shanks said. “Because we can’t be sure when this is going to move again, it’s not safe to have motorists underneath.”
CDOT crews and a contract company spent the day Tuesday assessing the situation from land and by helicopter. A downed power pole in a “precarious position” will be removed today, along with loose wires on the mountainside.
Equipment also will be moved into place that will allow workers to be placed at the top of the rockslide and propel downward while dislodging loose rocks, Shanks said. That process is expected to get started Thursday or Friday and likely will continue through the weekend, she said.
“The bottom line is, any of the rockfall mitigation is to reduce the risk; it’s certainly not to prevent it completely,” Shanks said. “We’ll do whatever we can within our power to reduce risk.”
The slide occurred 900 feet above the highway in an area known as Ruby Walls, along a curvy section of road just south of Bear Creek Falls, two miles south of Ouray.
Loose rocks covered a 200-foot stretch of U.S. Highway 550 up to 8 feet deep in some places Monday. Some rocks were up to 6 feet in diameter, Shanks said.
“It’s just a great deal of loose rock,” she said. “We have had rock fall in this area, (but) nothing like this from this high above at this magnitude.
“Anyone who drives the corridor knows there’s always rock coming down,” she said.
Rockslides typically occur during the spring in what is called the freeze-thaw cycle. At night, water freezes between the rocks and expands. When the ice melts, rocks come loose and the water seeps into new crevasses.
A similar pattern has been occurring this winter along the pass, Shanks said.
“It’s common all throughout the Rocky Mountain region,” she said.
About a 12-mile section of Highway 550 was closed from just south of Ouray to the top of Red Mountain Pass.
It will be the longest closure of Red Mountain Pass in recent memory. The pass closed for about four days during the winter of 2007-08 because of heavy snow, she said. An average of 2,200 vehicles travel the pass daily.
The closure makes for a long detour for drivers going from Ouray to Durango, who now must drive to Ridgway, over the Dallas Divide, over Lizard Head Pass, through Dolores, then take U.S. Highway 160 east. It is normally a 70-mile trip over Red Mountain Pass that now is a 168-mile trip (or a 98-mile detour).
“It’s not pretty,” Shanks said.
Motorists traveling from Ouray to Silverton, or vice versa, have the longest detour. It usually is a 22-mile trip over Red Mountain Pass that is now a 201-mile trip, Shanks said.
“Obviously, we want to get this open as quickly as possible, for everyone’s sake,” she said.
shane@durangoherald.com
An earlier version of this story misstated the name of Ruby Walls.
Alternate route
Those wanting to travel north on U.S. Highway 550 from Durango to Ouray and points beyond must take an alternate route until mitigation work is completed by Colorado Department of Transportation crews.
The best route is over Lizard Head Pass on Colorado Highway 145: Go west on U.S. Highway 160 to Mancos (27 miles), turn north on Colorado Highway 184 toward Dolores (17 miles), take Colorado Highway 145 over Lizard Head Pass to just past Placerville (75 miles), and take Colorado Highway 62 east to Ridgway, where it intersects with U.S. Highway 550 (23 miles).
The 143-mile route will take about 3 hours under decent driving conditions.
