ANCHORAGE, Alaska — Multiple skiers were reported trapped in the Alaska backcountry after being swept up in an avalanche, Alaska State Troopers said Wednesday.

The number of skiers and their conditions were not immediately available.

The slide happened late Tuesday afternoon near the skiing community of Girdwood, located about 64 kilometres south of Anchorage, Austin McDaniel, a spokesperson for the Alaska State Troopers, said in a text to The Associated Press.

“Troopers received a report of an avalanche that caught multiple individuals who were heliskiing yesterday afternoon near the west fork of 20 Mile River,” McDaniel said. “The company that they were skiing with attempted to recover the skiers but were unable to due to the depth of the snow.”

The size of the avalanche and the depth of the snow was not immediately known.

He said troopers will attempt to reach the site on Wednesday, and may need an aircraft to get to the remote spot well off the Seward Highway.

Girdwood is the skiing capitol of Alaska, and home to the Hotel Alyeska, at the base of Mount Alyeska, where people ski or snowboard. At the top of the mountain is the Seven Glaciers Restaurant, named for its view.

Each winter, 25 to 30 people die in avalanches in the U.S., according to the National Avalanche Center.

One person was killed in an avalanche in central Colorado on Feb. 22. Authorities in Grand County responded to what they described as a skier-triggered avalanche in a steep area known as “The Fingers” above Berthoud Pass. It was the second reported avalanche in the county that day.

That avalanche death was the third in Colorado this winter and the second fatality in less than a week in that state, according to the Colorado Avalanche Information Center. A Crested Butte snowboarder was killed Feb. 20 in a slide west of Silverton.

Elsewhere, three people died in avalanches Feb. 17 — one person near Lake Tahoe and two backcountry skiers in Oregon’s Cascade Mountains. On Feb. 8, a well-known outdoor guide was caught in an avalanche in Utah and was killed.