13-14

This natural avalanche is near Naya Nuki Bowl and the Throne area of the northern Bridgers. Photo: A. Newman

Debris from this fata avalanche on Crown Butte ranged from 5-15 feet deep and the victim was found 6 feet deep. Live recoveries when people are buried deeper than 6 feet are rare (about 4% of live recoveries are deeper than 6 feet according to the Avalanche Handbook, 3rd Ed.). The debris field extends to the trees in the background. Photo: GNFAC

The debris field from this fatal avalanche was roughly 900 feet by 400 feet....about 8 acres. This photo only shows about 1/3 of the debris. Photo: GNFAC

The locations of the three riders when the avalanche released are shown by the red X's. Dashed lines with arrows show the direction of travel and the escape route used by the two riders who were climbing whent the avalanche occurred. The victim was stopped and unable to escape.

This slide broke in a very thin rocky area. These are likely places to trigger avalanches. Once a collapse (or fracture) in the weak layer starts, it can propagate into much deeper areas. Photo: GNFAC

This weak layer was the weakest snow we have seen all season. Most places have square faceted crystals. This slope had large, cupped, striated, depth hoar crystals up to a centimeter in size. Photo: GNFAC

This slope had very thin snow considering the nearby Fisher Creek SNOTEL has over 10 feet of settled snow. This thin snowpack led to the formation of very weak depth hoar (6-10mm in size and Fist+ hardness). Photo: GNFAC

Montana has  five avalanche fatalities this season, four in the last 18 days.

From http://www.avalanche.org/accidents.php