A rockslide Friday night covered both lanes of La Posta Road (County Road 213) near south Durango city limits.
It was the second significant rockslide in Southwest Colorado within a week. The other occurred Jan. 29 on Wolf Creek Pass where a huge pile of rocks came down and closed the highway for 2½ hours.
Lisa Taylor of Durango said she was traveling south on La Posta Road about 6:30 p.m. Friday when she encountered another driver stopped amid the La Posta Road rockslide. It was roughly the same location where a truck-sized boulder came down in March 2023, she said.
“I got out to make sure (the other driver) was OK, because I didn’t know if he was actually involved in the slide or not – and he was just flabbergasted,” Taylor said. “ … I told him, ‘You probably ought to move because you don’t know if more is going to be coming down.’”
Taylor said she called law enforcement. Within 15 minutes, a La Plata County Road and Bridge crew was on scene clearing the road.
County spokesman Ted Holteen confirmed crews responded with a loader truck and a snowplow. He did not immediately have additional information about the rockslide.
Temperatures in Southwest Colorado were fairly cool in December and much of January, said Dennis Phillips, a meteorologist with the National Weather Service in Grand Junction. Temperatures have since warmed up, especially in late January and the first week of February, which could be leading to an early freeze-thaw cycle in some parts of the region, he said.
The freeze-thaw cycle can loosen rocks and cause them to come crashing down. Water gets into the crevices of rocks, where it can freeze and thaw, causing the cracks to expand over time.
In addition to milder temperatures, atmospheric river events have been shuttling large amounts of moisture to Southwest Colorado, Phillips said. Late last week, much of that moisture fell as rain in the lower elevations, which can also weaken rocks.
“It’s warmer than normal,” Phillips said. “ … And then we’ve started these (atmospheric river) events, which haven’t really brought in much cold air, just a lot of moisture. … We’ve had really wet snow instead of the really dry champagne snow.”
Another atmospheric river is expected to arrive early Tuesday, which “threatens to bring significant accumulations of heavy wet snow to the mountains through Thursday,” according to a hazardous weather outlook issued by the National Weather Service for the San Juan River Basin.
Forecasters said it was difficult to know if lower elevations like Cortez, Durango and Pagosa Springs would see more rain or more snow from the event. But temperatures are expected to begin cooling off Wednesday, which could mean snow for any lingering moisture in the later half of the week, Phillips said.
He expected 1 to 2 feet of snow to fall in the San Juan Mountains, with some areas receiving as much as 3 feet.
“It’s really unsettled,” Phillips said. “We’ve got a big open trough in the West that's going to stick around through the week and through the weekend, and there will be storm systems moving through it.”
shane@durangoherald.com
