Trip Planning for Island Park

Stability tests continually fractured on old, broken snowflakes just under a crust under the new snow about 16" deep

Small natural storm slab

This avalanche started on a slope above the rocks where there was more wind and then triggered another storm slab in the trees. It created a significant debris pile.

Light red lines indicate crown faces of this natural avalanche. It likely started as a wind slab/storm slab above the rocks, then dropped down onto the slope below triggering a storm slab avalanche that entrained a significant amount of snow and created a big debris pile.

Two Point release avalanches on south slope of Two Top. 1/30/25. Photo: K. Allred

Wide spread layer of Surface Hoar mid and upper elevations Two Top area

Shooting crack in a fresh wind slab near Mt Jefferson

North facing pit in Hellroaring Creek, Centennials

North facing snow profile Hellroaring Creek, Centennials

South facing snowpit Hellroaring creek, Centennials

S facing snow profile from Hellroaring Creek in Centennials

The GNFAC weather station at the top of Sawtelle provides wind, temperature and relative humidity information for forecasting (when it's not covered in a foot of rime ice. Photo: GNFAC

Photo: GNFAC

From the top of Sawtelle. Photo: GNFAC

Riders in the Centennial Mountains experienced almost constant whumphing at higher elevation and saw a couple of days old avalanche on a windl-oaded east north east facing slope. Photo: R. Gravett

Ice crust on trees from freezing rain last Saturday Dec 28 now covered by rime ice.

From obs on 12/29: "On our way out near the cabin I cut a line close to a creek to see if I could trigger something."

From obs on 12/29: "On our way out near the cabin I cut a line close to a creek to see if I could trigger something."

Thick and robust ice crust layer widespread above white elephant.  Photo: Ride Rasmussen Style 

Plumes of drifting snow in the Bridger Range as strong winds blasted the mountains. Photo: GNFAC

De-rimed Sawtell anemometer

Rock Creek natural avalanche

NE facing IP snowpit

E facing IP snowpit 

From IG: On 12/15 "Storm slab broke about 200’ above us as skinning up the hallway coming from the north side on the throne." Photo: Anonymous

Small windslab triggered on approach for inspection. Failure interface had 5 mm Surface Hoar. Soft slab, remote propagation onto the adjacent slope. Debris covered about half of the road bed.

Photo: J Hambelton 

Small windslab triggered on approach for inspection. Failure interface had 5 mm Surface Hoar. Soft slab, remote propagation onto the adjacent slope. Debris covered about half of the road bed.

Photo: J Hambelton

Small windslab triggered on approach for inspection. Failure interface had 5 mm Surface Hoar. Soft slab, remote propagation onto the adjacent slope. Debris covered about half of the road bed.

Photo: J Hambelton

Gusty winds transporting snow in Taylor Fork on Saturday. Triggered a 4-5 inch deep wind slab that propagated about 50 ft at the top of a north east facing slope at 9,500 ft.

Photo: JP

We are grateful for our partnership with the Friends of the Gallatin National Forest Avalanche Center. It is always a good time to get out in the field with our education coordinator, Shannon. Photo: GNFAC

The snow depth was 60-70 cm (2-2.5 feet) at the upper elevations of the Big Springs Loop around the Black Canyon area in Island Park. Photo: GNFAC

Surface hoar and near surface facets are now capped by this weekend's snow. The layers are buried 2-4" deep in the Black Canyon area of Island Park. Photo: GNFAC

WE facing snow at 8100 ft Cabin Ck

Cabin Creek snow cover

SE facing snow Cabin Creek

N facing snow Cabin Creek, 9000 ft

Big Sky Ski Patrol triggered this avalanche during mitigation work in The Wave on 11/26/24... "2-3' deep on an ice crust just above the ground with a 2# shot in the Upper rodeo. Volume was limited as most of the snow was loaded just underneath the cornice, but still produced a sizeable size 2... Other paths in the Lenin region ran meaty wind slabs, full track with no significant step downs." Photo: BSSP

Cracking on old, faceted, October snow hundreds of feet long. North facing near treeline. Photo: BSSP