New snow and darkness have hampered efforts to reach the site of an avalanche in the Jewel Basin Hiking Area where a skier has been missing since Wednesday afternoon.

Flathead County Sheriff Chuck Curry said Thursday morning that a team of seven on the Nordic Ski Patrol was unable to reach the site overnight.

"We attempted last night to get crews in there but due to the darkness and heavy snow conditions we weren't able to get to the slide," Curry said, adding that about a foot of snow fell overnight on the Swan Mountain Range. "It snowed all night."

According to the Flathead National Forest, the brother of the missing skier reported him missing from Camp Misery, the main access to the Jewel Basin, at around 2 p.m. Wednesday.

The avalanche reportedly occurred on the north side of Twin Lakes, about 2.5 miles by trail from Camp Misery.

"There was a party of two in there," Curry said. "One person was swept down the slide, the other was not."

Curry said the missing skier is believed to have an emergency beacon transmitter which would help expedite the search once the site is reached.

"Certainly those beacons will last a long time if the batteries are good," Curry said.

On Wednesday, Curry said searchers were trying to reach the scene from both the east and west sides of the Swan Mountain Range. An effort to reach the site at Twin Lakes by helicopter Wednesday was thwarted by cloud cover.

"It's a fairly difficult area to reach," Curry said. "We can get to Camp Misery by snowmobile ... but from there on it's pretty much skis and snowshoes."

The Sheriff's Office, North Valley Search and Rescue, Flathead County Search and Rescue and the Nordic Ski Patrol are involved in the search effort.

The Glacier Country Avalanche Center's advisory this week rated the avalanche danger above 5,500 feet as "considerable," especially on steep, open and wind-loaded slopes. The Twin Lakes area is right around 6,000 feet.