A North Dakota man was killed in an avalanche outside Cooke City on Wednesday.

The 31-year-old snowmobiler triggered a slide on the southwest side of Henderson Mountain in the Miller Creek drainage, according to the Gallatin National Forest Avalanche Center.

The victim was reportedly a very experienced rider who had been coming to Cooke City for the past eight years. According to the GNFAC, he remotely triggered the avalanche from a flat area and was buried about five feet deep when the steeper slopes above him released.

He and his partner had rescue gear and the partner tried to dig him him out. CPR was unsuccessful and Cooke City SAR responded within 10 minutes of the call-out and helped evacuate the victim. The avalanche broke on facets at the ground.

A detailed report is expected in the coming days.

Meanwhile, the GNFAC is continuing a backcountry avalanche warning for its entire advisory area.

The GNFAC warns that human-triggered and natural avalanches are likely. The avalanche danger is high in the Bridger, Gallatin and Madison Ranges, the Lionhead area outside West Yellowstone and mountains around Cooke City.Travel in avalanche terrain is not recommended and avalanche runout zones should be avoided.