This human triggered slide occured near History Rock in the northern Gallatin Range. Two people were caught, but nobody was injured. This specific area is not the main ski slope and is not traveled frequently by skiers. The slope angle was close to 40 degrees and the party had three separate "whumphs" on the traverse to this slope. Collapses are a red flag that the snow is very unstable and avalanche terrain should be avoided. All of us at the GNFAC thank them for relaying this story and picture. Photo JM