Snowmobile triggered very large avalanche Buck Ridge

From one of the riders that was caught, "The 3 persons involved were traveling across the slope about 20-30 yards up from the tree line parallel to the ridge line in the slide area when it broke, not high marking and not traveling uphill. One rider did increase his elevation while traveling across the slope but was never more than 1/4 of the way up when the slide was triggered."

Location
Northern Madison, 2020-01-04