Island Park / West Yellowstone--Snow and Avalanche Information
All of the photos on this page are "thumbnails", so--just click on them to enlarge.  The following 3 photos
in the photo documentary are courtesy of Doug Chabot--Gallatin N.F. Avalance Center.  The new "surface
hoar" photo (lower right, below) was shot at Henrys Lake on 1/25/06.
A photo documentary of LUCK and GOOD TIMING (photos below)
The slide path on the right in this photo is of
a 500' wide X 1,000' long event at 10,000'
elev. on Sheep Mtn. near Cooke City, MT on
1/22,05.  The slope aspect was N-NE.  Four
riders went up the slope and over the ridge
into the basin above.  The slide was
triggered as the last machine crossed the
fracture line, and none of the riders knew
they had started an avalanche.  A
sympathetic release occurred on the left
side of the slope at the same time.
This is a closeup of the triggered slide at
left.  Not knowing they had triggered the
slide, the 4 riders turned around in the
upper basin and rode over the blind crest of
the ridge in the left side of this photo, (see
tracks) and dropped over the 7' fracture
line. They took a nasty ride through the
rocks.  One was seriously injured.  They
were very fortunate they were not caught in
the avalanche when it slid.  The results
would have been MUCH different.
This column sheared in a snow pit near the
two avalanches above.  As stated by Doug
Chabot of the MT Avalanche Center:  "It
doesn't take much imagination to see the
consequences of a slide" under these  
conditions of thick, dense layers (as
evidenced by this large column) sitting on
top of a weak layer of faceted snow.  
Surface hoar layer on 1/25/06.  This is an
example of the type of crystals that form
on cold, clear nights, and become the
unstable layer that causes many slab
avalanches when buried by new snow.  

The background "paper" used on this page
is a digital enhancement of these crystals.