“We closed the basin as soon as we heard about it,” resort spokeswoman Riley Polumbus said. “We’re always looking out for the safety of our guests.”

The avalanche reportedly occurred around 2:30 p.m. on Jan. 25 on the steep and cliffy face below the Hellfire Run and above the Glory Hole Run at the bottom of the basin. No one was reportedly caught in the slide.

Staff from Flathead National Forest’s Flathead Avalanche Center investigated the avalanche the next day. Snowpack on the 35-degree or steeper southfacing slopes interspersed with rocky cliffs was shallower than in nearby areas, they reported.

“The slide was initiated by a human-triggered wet, loose avalanche from above, which then stepped down to a deeper layer and released as a slab,” the Center reported on their Web site.

Center staff reported that “a layer of moist, rounding facets sitting above the melt-freeze crust from mid-December” had failed to hold together with the rest of the snowpack.

The 100-foot wide avalanche traveled about 300 vertical feet and 600 linear feet. The height of the crown at the top of the slab ranged from 19 to 28 inches. Debris at the bottom was about 4-10 feet deep and 100 feet wide, the Center reported.

Polumbus said there weren’t too many people at the resort on the day of the slide, and the basin remained closed on Jan. 29.

“The conditions have not been ideal lately,” Polumbus said. “We’ve had a lot of warm, sunny days followed by cold, so the Hellroariing Basin area has become crusty.”

A slab avalanche in the Picture Chutes area of Hellroaring Basin prompted Whitefish Mountain Resort officials to close the basin to skiers and snowboarders on Sunday, Jan. 25.

“We closed the basin as soon as we heard about it,” resort spokeswoman Riley Polumbus said. “We’re always looking out for the safety of our guests.”

The avalanche reportedly occurred around 2:30 p.m. on Jan. 25 on the steep and cliffy face below the Hellfire Run and above the Glory Hole Run at the bottom of the basin. No one was reportedly caught in the slide.

Staff from Flathead National Forest’s Flathead Avalanche Center investigated the avalanche the next day. Snowpack on the 35-degree or steeper southfacing slopes interspersed with rocky cliffs was shallower than in nearby areas, they reported.

“The slide was initiated by a human-triggered wet, loose avalanche from above, which then stepped down to a deeper layer and released as a slab,” the Center reported on their Web site.

Center staff reported that “a layer of moist, rounding facets sitting above the melt-freeze crust from mid-December” had failed to hold together with the rest of the snowpack.

The 100-foot wide avalanche traveled about 300 vertical feet and 600 linear feet. The height of the crown at the top of the slab ranged from 19 to 28 inches. Debris at the bottom was about 4-10 feet deep and 100 feet wide, the Center reported.

Polumbus said there weren’t too many people at the resort on the day of the slide, and the basin remained closed on Jan. 29.

“The conditions have not been ideal lately,” Polumbus said. “We’ve had a lot of warm, sunny days followed by cold, so the Hellroariing Basin area has become crusty.”