Trip Planning for Southern Madison

From email: “These pics are from last June 10-11, after the pass reopened on Friday. I was skiing the Gardner headwall at 5:30, solo, when this monster released. Yah. The initial cornice collapse triggered and entrained a secondary slab of varying thickness whose crown is seen in one of the photos.”

From obs 5/7/23: "Natural R3-4, D4 ripped out a large chunk of the south face of Wilson during the last warm period I would assume. Debris everywhere and one large boat-sized pile even scoured a path further down than the rest of the debris. Looked to be a mix of wet loose and wet slab release from high up. Alpha angle at the bottom of the debris was 25 degrees" Photo: C. Ellingson

Give Big Gallatin Valley is May 4-5. The Friends of the Avalanche Center are participating again this year and thank you for your support. Between 6pm on May 4 through 6pm on May 5 you can support your favorite local non-profits. Donate Here.

Riders observed a natural, dry slab avalanche that occurred last week on a northerly aspect near the Sphinx. 

Approx coordinates of slide #1: 45.15872, -111.46923

Photo: L. Welles

Riders observed a natural, dry slab avalanche that occurred last week on a northerly aspect near the Sphinx. 

Approx coordinates of slide #1: 45.15872, -111.46923

Photo: L. Welles

Riders observed a small, full-depth wet snow avalanche on a southerly aspect near Pioneer Mountain. Photo: L. Welles

From Big Sky Ski Patrol: "Temps remained a little cooler than yesterday and generally topped out in the mid 40’s F. That didn’t stop the free water from moving
and continuing to destabilize the snowpack, primarily on solar aspects below 10,000’. Near full depth to full depth wet loose avalanches continued to naturally release in what was left of the A-Z’s as well as LRT which had not seen any activity yesterday." Photo: BSSP

This big wet slide buried the highway near Quake lake on 4/8/23. Photo: Z. Montano

This big wet slide buried the highway near Quake lake on 4/8/23. Photo: Z. Montano

From obs. 4/7/23: "I went through the area of Three Rivers Peak yesterday, and there had been a pretty nice cycle of large slides recently. One on the east face of Three Rivers broke 6-800’ wide 2-10’+ deep, and ran full track. It only had a couple inches of snow on it, so I think it ran sometime during the recent warm days. Some of the walls along the slide were over 20’ high, and I imagine the debris pile might make it through the summer. I also observed a couple older slides on E\NE aspects that were older, but not a whole lot smaller." Photo: S. Reinsel

From obs. 4/7/23: "I went through the area of Three Rivers Peak yesterday, and there had been a pretty nice cycle of large slides recently. One on the east face of Three Rivers broke 6-800’ wide 2-10’+ deep, and ran full track. It only had a couple inches of snow on it, so I think it ran sometime during the recent warm days. Some of the walls along the slide were over 20’ high, and I imagine the debris pile might make it through the summer. I also observed a couple older slides on E\NE aspects that were older, but not a whole lot smaller." Photo: S. Reinsel

From obs. 4/7/23: "I went through the area of Three Rivers Peak yesterday, and there had been a pretty nice cycle of large slides recently. One on the east face of Three Rivers broke 6-800’ wide 2-10’+ deep, and ran full track. It only had a couple inches of snow on it, so I think it ran sometime during the recent warm days. Some of the walls along the slide were over 20’ high, and I imagine the debris pile might make it through the summer. I also observed a couple older slides on E\NE aspects that were older, but not a whole lot smaller." Photo: S. Reinsel

Overall seemed like a deep HS (220 cm) versus other years I’ve seen here. High strength in pit (ECTP26), failure on facets below melt-freeze crust down 60 cm, and with no more obvious signs of instability. Felt weak snow deeper, but only dug in the top meter. North winds increasing throughout the day and any wind affected snow was shallow in depth. South aspects were crusted but protected N-facing or tree skiing was still great.

From obs 3/26/23: "Saw a couple small natural slides breaking in the new snow. The one on the small slope beside the road actually appeared to have broken when a snow bike crossed the top just off the side of the road." Photo: J. Weingarten

From obs 3/26/23: "Saw a couple small natural slides breaking in the new snow.... occurred in the afternoon sometime" Photo: J. Weingarten

Photo: R. Lindsey

On our ride up the Taylor Fork, we saw several natural avalanches that appeared to have broken about a week ago. This avalanche was in Sage Basin. Photo: GNFAC

On our ride up the Taylor Fork, we saw several natural avalanches that appeared to have broken about a week ago. This avalanche was at the head of Sage Creek. Here, Alex is investigating the layering within the snowpack that lead to the avalanche. Photo: GNFAC

On our ride up the Taylor Fork, we saw several natural avalanches that appeared to have broken about a week ago. This avalanche was in Sage Basin. Photo: GNFAC

On our ride up the Taylor Fork, we saw several natural avalanches that appeared to have broken about a week ago. This avalanche was in Sunlight Basin. Photo: GNFAC

On our ride up the Taylor Fork, we saw several natural avalanches that appeared to have broken about a week ago. This avalanche was in Sunlight Basin. Photo: GNFAC

We saw a natural avalanche near Bacon Rind into the Gallatin River. Photo: GNFAC

Skiers noted a 1-2’ deep slide on the west-facing road cut just north of the Bacon Rind pullout. Photo: S Reinsel

Skiers noted an avalanche on Red Mountain that spanned about 2000’. They estimated it was 1-3’ deep in the newer snow, for the most part, but a portion of it broke 15’+ deep and ran at the ground. Photo: S Reinsel

Skiers noted an avalanche on Red Mountain that spanned about 2000’. They estimated it was 1-3’ deep in the newer snow, for the most part, but a portion of it broke 15’+ deep and ran at the ground. Photo: S Reinsel

Via IG: “Large natural avalanche on the east side of redstreak peak down near West Yellowstone. 

And then another natural one right on the shoulder of white peak on the boundary.” Photo: S. Mooney

Via IG: “Large natural avalanche on the east side of redstreak peak down near West Yellowstone. 

And then another natural one right on the shoulder of white peak on the boundary.” Photo: S. Mooney

From IG message: "3 different slides lionhead area. One was very big the run out was 20 feet tall and quarter mile long" Photo: T. Urell

Across the road from Bacon Rind at 7,070' on a west facing slope I saw a small skier triggered slide that ran into the Gallatin River. 

On Buck Ridge today (3/5/23) we found fresh, unstable drifts. This fresh slab was 4-6" deep. Cracking like this is a sign that wind slabs will avalanche on steeper slopes. Photo: GNFAC

Skier triggered avalanche on Elephant Mtn. 3/4/23. SS-ASu-R2-D1.5-I

Vertical Fall: ~700' Distance Traveled: ~1000' Aspect: 15 N Elevation of start zone: 9645'

Skier triggered deep slab avalanche on NE face of Hyalite Peak 3/4/23.

A cornice collapsed on Monday, triggering an avalanche on the slope below. Dave Zinn assesses the layers in the flank. Photo: GNFAC

A cornice collapsed on Monday triggering an avalanche on the slope below. Photo: GNFAC

A rider triggered an avalanche on a small slope in the Cabin Creek area. Photo: K Bye