In a news release Wednesday, the U.S. Bureau of Reclamation announced County Road 1812, which provides access to the Blue River below the Green Mountain Reservoir spillway, will remain closed, likely throughout the summer.

The road has been closed since April, when mud and rock slides blocked the roadway. Now, the bureau says that unstable slope conditions above the road pose a threat to public safety.

Anna Perea, a bureau public affairs specialist, wrote in an email to Summit Daily News that land in the Heeney area has a layer of cretaceous shale, a type of rock known to be unstable and have the potential to “creep” downward if on a slope.

Excess draining or ponding of water and physical changes to a hillside can cause the creep to occur more quickly, Perea wrote. One such physical change would be a road being cut into the hillside, which is the case with C.R. 1812. 

Bureau geologists and engineers this month visited the site of the mud and rock slides that closed the road in April and determined the slide area and scarp, or slope, above the road is unstable, Perea wrote. She added that April slides left the earth at the top of the slope undercut, and water from runoff is seeping from the middle of the slope.

“Added precipitation could cause the slope to fail,” Perea wrote. “Groundwater or surface water from precipitation and snowmelt could take several days after precipitation to initiate additional movement above the road.”

Perea wrote that the geologists believe rockfall and sliding will continue in the coming months, especially if there is heavy rain in the area. They, the engineers and other bureau staff decided to close the road “until the unstable slope is mitigated or the slide area dries up naturally, and there are no signs of movement/rockfall activity.”

A vehicle passing by when material saturated by rain or snowmelt slides down could be pushed off the roadway, Perea wrote.

The bureau is working on short-term and long-term solutions to stabilize the slope and reopen the road. Perea said the road needs a short-term slide mitigation plan so workers at the Green Mountain Power Plant, accessed by C.R. 1812, can safely get to and from work. The plant remains open, and Perea wrote that staff are trained to assess road conditions.

Without access to C.R. 1812, anglers and recreationists will have more difficulty accessing the lower Blue River, something local anglers say a land swap finalized this year already made difficult.

Silverthorne resident Zack Shollenberger said the closure will affect whitewater rafters as well. Shollenberger said he uses C.R. 1812 to access the lower Blue River “almost every weekend in the summer.”

“Spring is badass when the water gets moving,” Shollenberger said. “It’s a really big rapid, down towards the end of it. It’s great for whitewater (rafting) — a really tight canyon.”

The area of the Blue River accessible from C.R. 1812 is one of the only raftable tailwaters in Colorado, Shollenberger said. Tailwaters are areas where water in a lake or reservoir flows out into a river.

Shollenberger said tailwaters often lead into canyons, which is the case for the Blue River as it leaves Green Mountain Reservoir. Canyones, Shollenberger said, often equate to good fishing and rafting.

“(The road closure) is gonna cut out 100% of angling opportunity and 100% of whitewater opportunity for the peak of the season,” Shollenberger said about the Blue River tailwater canyon.

Rafting on this part of the Blue River is strictly recreational, Shollenberger said, meaning rafting companies can not get permits to do business on it. Without access, Shollenberger said it will be harder to avoid the crowds this summer.

“That was always a really cool option, to not really have to worry about a lot of people around,” Shollenberger said. “We’ll be searching for water this season.”

Members of the public who would like to comment on the road closure can email Perea at aperea@usbr.gov.