AVALANCHE INCIDENT
                   PORTAL CREEK, GALLATIN RANGE, SW MONTANA
A group of snowmobilers left the Bozeman area to go for a night ride on
Tuesday, January 9th, 1996.  They left the parking area at Portal Creek at
about 4:30 pm and headed toward Windy Pass, which is located about 12 miles
east of Big Sky Ski Area.  Breaking trail in the dark, they tried working their
way down an open slope.  One person was riding down the slope and two were
walking near the bottom of the slope when they likely triggered an avalanche
above them.  They were swept about 30 yards through trees.  One of the victims
swam (he later reported that he had been in "several" avalanches before and
swimming always seemed to work well) and ended up on top of the debris.
Another victim was buried with only his head out of the snow, and the third
victim was totally buried.  Luckily, that third person had his foot touching
the person buried to his neck and could lightly kick that person.  The rider
who was not caught and the person who ended up on top of the debris quickly dug
out both victims.  No one in the party was wearing avalanche beacons.  The
snowmobile (brand new...only 30 miles on it) was wrapped around a tree and
totalled.
We have not been to the avalanche site.  The slide was reportedly broke out 2
to 3 feet deep and was 150 yards wide.  Failure was likely on a buried layer of
surface hoar and small grained faceted crystals that formed during our cool,
dry weather over Christmas.  Since that dry spell, we have received anywhere
from 1 1/2 to 3 feet of snow throughout our region and are now getting strong
winds.  Not surprisingly, we've had extensive avalanche activity through
southwest Montana over the past two weeks, including at least 5 snowmobile
triggered avalanche in the last 2 days.
Mistakes:  unaware of avalanche conditions, travelling through unfamiliar
avalanche terrain at night, not carrying the proper equipment.  They are just
fortunate that luck was on their side!
Any question/comments, contact Karl Birkeland or Ron Johnson at (406)587-6984.
Karl Birkeland
Avalanche Specialist
Gallatin National Forest Avalanche Center