DENVER (KDVR) — The Colorado Avalanche Information Center said a “very large avalanche” was triggered remotely by skiers on Mount Trelease Tuesday.

While at least three groups were in the area, no one was injured. The CAIC said the D3 avalanche was triggered at about 12:30 p.m. by skiers from low-angle terrain, below steep adjacent slopes. An avalanche on the same slope in 2021 killed a snowboarder who was caught in the flow.

Because of elevated risks in current high country conditions, the CAIC has issued a special avalanche advisory that will last through Wednesday, Jan. 1, afternoon, emphasizing the risks across Colorado.

D3 avalanches like the one triggered Tuesday have enough force to bury or destroy property like cars, small buildings or trees. Larger avalanches, such as a D4 or D5, have enough force to destroy rail cars, several buildings or a small village.

The organization warned that with current conditions, backcountry users can trigger large, potentially deadly avalanches from adjacent slopes or even from flat terrain below a steep slope. The person who triggers the avalanche could be up to 1,000 feet from the event, the CAIC stated.

“These conditions make the backcountry particularly hazardous during this busy holiday period when many are out enjoying the fresh snow,” the CAIC warned in its alert.

Most of Colorado’s high country was forecasted to have “considerable” avalanche danger on Monday and Tuesday.

Normally safe backcountry routes may be unsafe

The advisory is specifically designed to alert backcountry recreationists that conditions require heightened awareness and precautions. The alerts are issued when potentially dangerous conditions pose safety risks to many people such as a big storm during a holiday weekend.

“We’re less likely to see heavy snowfall the rest of the week, but we are still very worried about an avalanche accident,” said CAIC Director Ethan Greene in a Tuesday release. “The big storms hit us over the weekend and left us with some very dangerous avalanche conditions. The danger is less obvious than what people are used to. We’re seeing people trigger avalanches from low-angle terrain and the bottom of avalanche paths. Some slides have been triggered from over 1,000 feet away.”

The organization said that normally safe routes may not be safe right now as dangerous avalanche conditions persist.

“People traveling in the backcountry need to choose routes that avoid crossing under steep slopes. The routes you’re used to using and the safe spots you often use may not be safe right now,” Greene said.

The organization said that Colorado’s current avalanche conditions are “very similar” to Utah’s current conditions, where one person died in avalanches in the past few days.