Cooke City, 2018-02-22
Northern Gallatin, 2018-02-22

Skiers up Mt Blackmore triggered small wind slabs near the ridgelines. These slides were small, but could produce high consequences if triggered in steep terrain. Photo: C. Ronemus 

Lionhead Range, 2018-02-21

This picture was taken on Monday, February 19, at Lionhead on an east-facing slope. The wind slab was likely triggered by a cornice chunk hitting the slope. Photo: T. Johnson

Northern Madison, 2018-02-20

A skier reported natural avalanche activity on east facing slopes in Middle Basin. Photo: J. Die 

Bridger Range, 2018-02-20

Cornices have grown very large and are severely overhung. They sometimes break much further back than anticipated and can take you for a nasty, sometimes fatal ride. Plus they are excellent at triggering avalanches in the wind pillows below them. This photo was taken on the ridge north of Bridger Bowl. Photo: GNFAC

Bridger Range, 2018-02-20

A skier observed large cornices north of the Bridger Bowl boundary, despite the east wind several days ago eroding some snow at higher elevations. Always give these beasts a wide berth, and remember that they can break farther back than expected. Photo: H. Coppolillo

Bridger Range, 2018-02-20

Cornices break easily and have killed many unsuspecting people. They fool us into thinking we are on solid ground when, in fact, we are standing on a thick diving board of snow. Give cornices a wide berth.

Cooke City, 2018-02-19

This natural avalanche was observed on an east aspect around 9000' on Mt. Republic.  Crown estimated at 4-6' deep, on a rocky wind-loaded convex rollover.  3" of SWE and heavy winds have drifted wind slabs at various elevations. Photo: B. Fredlund

Northern Gallatin, 2018-02-19

Skiers up Hyalite triggered this cornice on Mt. Bole as they traversed along the ridgeline. The cornice triggered a small slab avalanche that took out the skiers skin track. Cornices are under a lot of stress from this week's snow and wind and should be given a wide distance along ridges. Photo GNFAC 

Southern Madison, 2018-02-19

Snow rangers observed this slide on a heavily wind loaded slope along a prominent ridgeline going into Tepee Basin. A good example of windward (scoured) and leeward (wind-loaded/corniced) side of ridgelines. Photo: J. Norlander

Northern Gallatin, 2018-02-18

A skier in Hyalite observed this avalanche in the meadow below Mt. Blackmore. Strong wind over the weekend drifted snow into wind slabs at all elevations. Photo: J. Stewart

Northern Gallatin, 2018-02-18

Cornices are extra large with all the generous snow we've had this season. These monsters and wind loaded slopes are the main avalanche concerns to start the week. On Buck Ridge today, we found 16" of new snow from the weekend's storm. We didn't see any avalanches or glaring signs of instability, and the snowpack is generally stable besides new snow and fresh wind slabs. Photo: GNFAC

Northern Gallatin, 2018-02-16

A skier in Hyalite observed these dry loose avalanches in steep terrain yesterday. Although not as dangerous as slab avalanches, sluffs can catch and carry skiers or riders into rocks or trees. Sluffs can also act as triggers for larger slab avalanches. Photo B. Vandenbos

Southern Madison, 2018-02-15

This slide occurred up Cabin Creek in the southern Madison Range. It was a heavily wind loaded slope that was triggered by a snowbiker. Fortunately, nobody was injured in this event. Photo. D. Benson 

Cooke City, 2018-02-15

A widespread natural avalanche cycle occurred in the mountains west of Cooke City in Yellowstone National Park. This photo was taken on the 12th of February, so these slides likely occurred last weekend. What's interesting is the mountains right outside of Cooke City did not see this kind of activity. Photo B. Fredlund 

Northern Gallatin, 2018-02-14

Doug stands in the a snowpit on a NE facing slope at 7,770 ft. on Mt Ellis. The snowpack is roughly 5' deep with no discernable weak layers. This is one of the best snowpacks we've seen on Mt Ellis in years. Photo: GNFAC 

Cooke City, 2018-02-14

This large, natural avalanche occured likely when the avalanche Warning was issued on Thursday or Friday (2/8 and 2/9) of last week. Another view of it:  Photo: S. Logan

Lionhead Range, 2018-02-12

Surface hoar 1.5-2' deep near West Yellowstone is capable of producing an avalanche, but becoming difficult to trigger. It can be easily identified as a gray stripe on a flat snowpit wall. Photo: GNFAC

Lionhead Range, 2018-02-12

A layer of 4-9mm Surface hoar crystals are buried 1.5-2' deep in the Lionhead area near West Yellowstone. (3mm grid) Photo: GNFAC

Cooke City, 2018-02-12

This slide caught and buried a rider on Saturday 2/10. His partners found him with just one finger sticking out and uncovered his face in 30 seconds. His sled was buried 4-6' deep. The slide broke 2-4' deep on a south aspect at 8,800'. Estimated 40 degrees steep. Photo: F. Madsen