Detailed Accident Report
Submitted By: Scott Schmidt, GNFAC
Place: Elk Creek drainage of the Crazy Mountains near Livingston Montana
Summary: 1 snowmobiler caught, buried, and killed
Another avalanche killed a snowmobiler in the Crazy Mountains on February 2, 2003. The following report was compiled by Scott Schmidt.
ELK CREEK AVALANCHE FATALITY 02 February 2003
One snowmobiler was caught and killed in an avalanche that occurred in the Elk Creek drainage of the Crazy Mountains near Livingston Montana. The avalanche released on a wind-loaded slope, with a north aspect. The slope angle, which averaged 32 degrees, increased to 42 degrees at the crown. The crown averaged 1.5 feet deep, and was approximately 200 feet in width. The avalanche ran 400 vertical feet, with an a-angle of 25 degrees. US classification of the avalanche is SS-4-AS-O.
12 inches of new snow fell during the night prior to the avalanche. Winds were not strong with this storm and the new snow did not appear to be wind affected on the majority of the slope, although there was evidence of wind loading that occurred previous to the storm. Temperatures were seasonal with highs in the mid-twenties and lows in the teens.
33-year-old Bryan LaHaye of Wilsall, Montana was riding with two friends in the Elk Creek drainage of the Crazy Mountains north of Livingston, Montana. At approximately 3:30 in the afternoon LaHaye rode part way up a north-facing slope. Conflicting reports make it unclear if he became stuck or simply stopped on a bench part way up the slope. Either way, the slope failed under the additional weight of LaHaye and his snowmachine, with the fracture occurring 200 vertical feet above him. LaHaye was completely buried approximately 50 feet above his snowmobile, which was partially buried at the toe of the debris. No one in the party was wearing a transceiver or carried rescue gear.
One of the remaining party rode 5 miles to a ranch house where he initiated the call for SAR personnel. This call came at approximately 4:30. The other survivor remained on the scene looking for surface clues. Four SAR personnel arrived on the scene at about 6:30. The victim was located by a course probe line and recovered about an hour later.
The avalanche released on a layer of small grained, faceted, crystals that formed during the second week of January. This layer had subsequently been buried by 8 inches of wind-affected snow. The addition of 12 inches of snow overnight on the 1st of February caused most of the north facing slopes in the basin to avalanche naturally. While this accident occurred outside of the GNF Avalanche Center advisory area, this weak layer is similar to other layers that formed during this same time frame throughout Southwest Montana. The avalanche danger had been high or considerable in most of the advisory areas previous to the avalanche. The slope in question was low angle for the most part, with only the last 100 vertical feet having a slope angle greater then 35 degrees. This allowed the snow on this slope to remain in place until the additional weight of a machine and rider was added. Stability tests, preformed on February 3rd, adjacent to the slope that avalanched, found the weak, faceted layer to be very sensitive. If you have questions about this incident please feel free to call me at 406-587-6984 or email me at firstname.lastname@example.org.
Scott Schmidt Avalanche Specialist Gallatin National Forest Avalanche Center 4 February 2003