Update: On Tuesday, CDOT announced road crews were nearing completion of the first phase in a two-stage cleanup operation on U.S. Highway 6, Loveland Pass.

The highway section between Loveland Ski Area and Arapahoe Basin Ski Area has been closed after a landslide left the roadway buried under up to 20 feet of mud and silt.

CDOT said as of Tuesday around 2 p.m., approximately 85% of debris removal in the travel lanes has been completed. Crews, supported by more than seven tandem dump trucks, are continuing with heightened safety precautions due to the unstable slope above the highway.

According to CDOT, once all debris is removed, CDOT engineering teams will begin phase two — assessing slope stability and completing any final cleanup before the road can be safely reopened to traffic.

“While crews are working diligently to clear the slide, there is no estimated timeline for when Loveland Pass will reopen,” CDOT said in a statement Tuesday afternoon. “The pass will remain closed until the roadway is deemed safe. Motorists, hikers, and cyclists are urged to stay clear of the area until the clean-up is complete.”

Monday: U.S. Highway 6 between Loveland Ski Area and Arapahoe Basin Ski Area remains closed due to a landslide on the north side of the pass, according to the Colorado Department of Transportation.

The closure happened about 5:30 a.m., Sunday “due to (a) mountain slide that is currently approximately 100 ft. wide and 15-20 ft. deep and still active,” according to a CDOT alert.

Rebecca Richmond said on the CDOT Facebook page that she encountered the slide at about 4:45 a.m. Sunday while on her way to Denver International Airport.

The slide happened at mile point 226, CDOT said.

According to a news release on Monday from CDOT, the material above the roadway became saturated by melting snow and slid onto the highway.

The clean-up operations will be done in two stages. The first stage will remove the mud and silt from the travel lanes. Once that is complete, the slide will be assessed again to make sure it is stable. The second stage will clean the remainder of the slide.

The closure did not impact Arapahoe Basin Ski Area, which had it closing weekend Saturday and Sunday. 

“US Highway 6 from Keystone is OPEN,” the resort said in a Sunday Facebook post. “The highway east of A-Basin is closed. Skiers and riders can join us for closing day, but they have to drive through Keystone. Loveland Pass is closed.”

This isn’t the first time a landslide happened at this location.

According to CDOT, there is record of this area partially sliding in 2003, however, it stabilized on its own shortly afterward, with no history of movement over the past 22 years.

Due to the Loveland Pass closure, CDOT is escorting trucks carrying hazardous materials through the I-70 Eisenhower-Johnson Memorial Tunnels (EJMT) at the top of the hour.

At that time, traffic will be held for hazmat vehicles to drive through. Hazmat vehicles are not allowed through the EJMT due to safety concerns, but when Loveland Pass is closed, they are escorted through the tunnel.

Greg Fulton, president of the Colorado Motor Carriers Association, said there’s a protocol for closures of Loveland Pass and moving hazardous materials through the tunnel, usually in the winter, but the delays that may be required can cause problems for drivers whose allowable driving hours expire while they are waiting to be escorted through the tunnels.

“What happens is when we’re looking at a fuel run, let’s say you’re trying to take jet fuel to the Aspen airport, and you can do that turn within the daily allowable driving hours,” said Fulton. “When you add a wrinkle like this in there, then it becomes very iffy. What happens at that point is either the driver has to shut down somewhere along the road and take a 10 hour rest period, which kind of throws everything else on the schedule out of whack.”

Fulton noted that almost all fuel, including diesel, gasoline and even aviation fuel travel across the Continental Divide in tanker trucks because there are no delivery pipelines through the mountains.

CDOT officials had no estimate for a re-opening. Check the latest road conditions on COtrip.org or on the COtrip Planner app.