Photos

Avalanche observed in Yellowstone National Park on Feb 11. Broke under weight of recent heavy snowfall in the area. Photo: B. Fredlund

Avalanche on E facing ridgeline near Divide Peak. Likely triggered by cornice fall from ridgeline. Photo: G. Antonioli

A natural avalanche near Asbestos Lake in the Northern Madison Range. NE aspect around 9,500'. Ran 600'+ into flat terrain. Photo: A. Whitmore

A layer of near surface facets was propagating in stabiliy tests on an east facing slope in Beehive Basin. It's worth digging and looking for this layer before committing to steeper slopes. Photo GNFAC 

Large cornices are forming. Give these monsters a wide berth when traveling along the ridgelines and be cautios when traveling underneath them. Photo GNFAC 

A historic natural avalanche ran between Friday (2/10) and Saturday (2/11). The avalanche put 10 to 20 feet of debris across the road and ran the entire width and length of the path. This area had 9.5" of SWE over the last eight days and strong wind. Photo: M. Dixon

A historic avalanche on Henderson Mtn. covered Lulu Pass road with 10-20 feet of debris, 1000' across the runout zone. Photo: M. Dixon

A historic natural avalanche ran between Friday (2/10) and Saturday (2/11). The avalanche put 10 to 20 feet of debris across the road and ran the entire width and length of the path. This area had 9.5" of SWE over the last eight days and strong wind. Photo: D. Armstrong

Ski patrol triggered this slide with explosives on Friday (2/10). The slide broke on weak snow over a crust in a shallow snowpack on a slope that slid earlier this year. Photo: BSSP

This avalanche was observed on Friday, Feb. 10th near the end of an historic storm in Cooke City. Heavy new snow and strong wind created huge slabs that could break deep within the storm snow. Photo: D. Armstrong

This avalanche was observed on Friday, Feb. 10th at the end of an historic storm in Cooke City. Heavy new snow and strong wind created huge slabs that could break deep within the storm snow. Photo: GNFAC

This avalanche was triggered by a snowmobiler in Taylor Fork on the way in to Sunlight Basin. It was north-facing and broke 18" deep, possibly on a layer of surface hoar. Photo: C. Krob

This natural avalanche off the ridge at the top of Bostwick canyon was the result of heavy wind-loading from S-SW winds. Photo: Bridger Bowl Ski Patrol

A skier up Deer Creek in the northern Madison Range got unstable results on a layer of surface hoar 25 cm's below the surface. This pit was dug on an E facing slope around 7,800 ft. Photo A. Whitmore

These slides occurred south of Cooike City on Mt Republic. These slides were generally on an E, SE aspect, and around 8700' in elevation.  Crowns looked to average about 2' deep. Photo B. Fredlund 

Here's a glimpse of the avalanche activity and weak layers we are concerned with today. Photo: GNFAC
 

Trees that were broken and knocked over by a large natural avalanche that ran 2/4-2/5. Photo: K. Miller

The toe of the debris from an avalanche that ran naturally on 2/4-2/5. The debris crosses the drainage from the right and goes up a small hill on the left. Photo: K. Miller

Looking up the slide path of avalanche that ran naturally the weekend of 2/4-2/5. This slide ran to flat terrain, across a creek, and broke trees 6" in diameter. Photo: K. Miller

Outline of crown of an avalanche that ran naturally the weekend of 2/4-2/5, on a S-SW aspect in Sheep Creek near Cooke City. The slide ran to flat terrain, across a creek, and up a small hill. It broke trees 6" in diameter. Photo: K. Miller