12-13

As of Halloween day, the snowpack near Cooke City above 9000 ft is 2 ft deep on all aspects.  It is warm, moist and dense.....for now.  First and foremost, there is plenty of snow for avalanches.  Second, it looks like it could form a solid foundation for the snowpack; HOWEVER, a lot can change in the next month.  We'll have to wait and see how it evolves.  It could stay strong or it could become very weak.  Photo: GNFAC

This natural avalanche occured on Henderson Mountain near Cooke City.  Even though it may still be fall, there is enough snow for avalanches in many areas.  Have fresh batteries in you beacon, make sure all your gear is in good shape, and most importantly pay attention to mother nature's warning signs like heavy snowfall, heavy wind loading, collapsing or cracking, and recent avalanche activity.  Photo: GNFAC

On Sunday, October 28, three male skiers in the northern Bridger Range were ascending a south-facing slope immediately south of Frazier Basin when they triggered an avalanche. All three were partially buried. Two were injured. The avalanche was estimated to be three feet deep, 100 feet wide and ran approximately 600 feet vertical. US classification is SS-AS-U, R2, D2.

Three skiers triggered and were caught in an avalanche in the northern Bridger Range as they skinned uphill.  They were all swept to the bottom getting beat up on rocks along the way.  The skiers were all partially buried.  One was injured and was evacuated by Gallatin County Search and Rescue.  Photo: GNFAC 

The avalanche broke near the ridgeline where it was windloaded.  The skiers felt the slope "whumph" and then watched cracks propagate above them before they were all swept downhill and partially buried. They got beat up on the rocks, which injured one, but there was also plenty of snow to completely bury them, which luckily did not happen.  Photo: GNFAC

 This slide was triggered by a skier near Ross Pass in the Bridger Range.  Wind loaded slopes are the most prone to avalanche activity and should be approached with caution.  Photo Ben VandenBos

SNOWPACK AND AVALANCHE:

Yesterday, we received our first ski observation from Cooke City.  Aside from finding a grizzly bear in the trees, a group of skiers found a settled base of 16-18 inches near Daisy Pass with wind loaded areas holding snow two to three feet deep.  Currently, the mountains around Cooke City have received the most snow; the remainder of our advisory area has about 4-6 inches on the ground. 

The snowpack is so thin that grass is sticking up in the foreground.  Moments before the avalanche was triggered it would be easy to assume that there was not enough snow to slide.  A climber triggered this small pocket in 2004 as he approached an ice climb on the north face of Sphinx Mountain. Small slopes and thin snow cover are potentially dangerous, especially when the slopes are atop a cliff. Photo: Jim Earl

Small avalanches on small slopes are dangerous. This photo was taken in 2004 on the approach to the ice climb on the north face of Sphinx Mountain.  The slab is thin, but could easily sweep a person off a cliff.  This photo was taken a week or so before the avalanche that killed two climbers on a nearby, similar sized slope. Photo: Jim Earl