On the morning of March 23, 2023 near Daisy Pass, two snowmobilers were stuck on a slope and a third was snowmobiling up to help when a large avalanche was triggered. The two stuck riders were caught and carried, and one of them sustained potentially life-threatening leg injuries. The third rider was able to safely ride off the slope and was not caught by the avalanche. Photo: B. Zavora
Compiled from multiple observations-
One observed noted "Large avalanche in the Bunny Ears on Elephant Mtn. Best guess is HS-N-R3/4-D3-O."
Second observer noted: "Skiers left flank appears at a distance to be 8-10' and by the looks of the bed surface I'd guess this was on advanced facets on an early season (late Oct/early Nov) ice crust."
Third observed submitted photos of slide from above.
From Ben Zavora at Beartooth Powder Guides on 3/23/23 at 11:00am: "Two guys stuck on slope next to chimney rock. SW aspect. Third guy rode to help and triggered the avalanche. No one buried. One rider broken tib/fib and possibly a femur getting life flighted out right now."
<p><span>In the southern half of the advisory area, we have two issues. First, smaller avalanches could fail within the 5-9” of snow that fell earlier this week. The resulting avalanche will generally be small, with severe consequences primarily dictated by the complexity of the terrain. Watching for signs of instability and a quick snowpit will provide the needed information to avoid this problem. The second concern fits into a category that we consider “high consequence, low probability” events (</span><a href="https://www.youtube.com/watch?app=desktop&v=Og9Usv82CdU&feature…;). This is our deep slab avalanche problem. </span></p>
<p><span>Stability has greatly improved since last week’s avalanche warning and significant avalanche cycle (</span><a href="https://youtu.be/ncKRJpdC-iE"><strong><span>Lionhead video</span></strong></a><span>, </span><a href="https://www.youtube.com/watch?v=KJ0l4TlIh_I&list=PLXu5151nmAvTi1DBS… Fork video</span></strong></a><span>). As I discussed in my </span><a href="https://youtu.be/X13MlPQaVqE"><strong><span>video</span></strong></a><s…; above Hebgen Lake yesterday, we remain wary because if you find the wrong spot, and get caught. The result could be unsurvivable. In Cooke City, the fourth rider on a slope triggered a huge avalanche on Henderson Mountain this weekend. Thankfully, he wasn’t caught. If it hadn’t been him, it could have been the tenth or the fiftieth (</span><a href="https://youtu.be/cTqk-2D4nwY"><strong><span>Cooke City avalanche video</span></strong></a><span>). </span></p>
<p><span>If you take your chances with low-probability deep slabs, be obsessed with the potential consequences. Rely on your safe travel protocols, choose smaller slopes rather than large ones, and select less wind-loaded terrain (generally, if there is a cornice directly above it, avoid it). </span></p>
<p>The danger is MODERATE.</p>
<p><span>On a non-avalanche-related note, I saw the markings from a bear coming out of hibernation in the Lionhead area—time to carry bear spray. I know, if it's not one thing, it's another.</span></p>
<p><span>Avalanches are unlikely today in the northern half of the advisory area. Isolated instabilities that you encounter are likely to be small, involving recent snow and surface-level wet snow. The negative consequences of these small avalanches will generally be dictated by the terrain rather than the size of the slide. </span></p>
<p><span>Yesterday, skiers at Mount Blackmore noted wet and dry loose snow avalanches (</span><a href="https://www.mtavalanche.com/node/28770"><strong><span>observation</span…;). The day before, snowboarders in Big Sky and skiers near Divide Peak noted similar new snow instabilities (</span><a href="https://www.mtavalanche.com/node/28763"><strong><span>observation 1</span></strong></a><span>,<strong> </strong></span><a href="https://www.mtavalanche.com/node/28762"><strong><span>observation 2</span></strong></a><span>) and</span> I saw loose snow avalanches that ran surprisingly far on an ice crust in Frazier Basin (<a href="https://youtu.be/a1aOgLTtZio"><strong><span>video</span></strong></a>). Warm temperatures and time have largely improved these instabilities. <span>Use a quick pit to test the upper few feet of the snowpack to uncover isolated instabilities that remain.</span></p>
<p>The last deep slab avalanches in the north were a little over two weeks ago (<a href="https://www.mtavalanche.com/node/28642"><strong><span>Bridger Range details and photos</span></strong></a>, <a href="https://www.mtavalanche.com/node/28455"><strong><span>Hyalite Peak details and photos</span></strong></a>). This problem is not out-of-mind, but these avalanches are now unlikely.</p>
<p>Follow safe travel protocols every day in avalanche terrain. The danger is rated LOW.</p>
<p>Please share avalanche, snowpack or weather observations via our<a href="https://www.mtavalanche.com/node/add/snow_obs"><span> </span></a><a href="https://www.mtavalanche.com/node/add/snow_obs"><strong><span>website</s…;, email (<strong>mtavalanche@gmail.com</strong>), phone (406-587-6984), or Instagram (#gnfacobs).</p>
<p><span>The most likely scenario is triggering relatively <span>small avalanches within the 7-9” of snow that fell earlier this week. Severe consequences will be largely dictated by the complexity of the terrain. The less likely deep slab avalanche problem is more vicious. If you take your chances with low-probability, high-consequence deep slabs, be obsessed with the potential consequences. Rely on your safe travel protocols, choose smaller slopes rather than large ones, and select less wind-loaded terrain. </span>Watch our <a href="https://www.youtube.com/watch?v=O-lUMunzE1k"><strong><span>video</span>…; from last week on the deep avalanches in Island Park, check out this <a href="https://www.mtavalanche.com/images/23/deep-avalanche-mt-jefferson"><str…; from a snow biker near Jefferson and read this thorough <strong><a href="http://www.mtavalanche.com/node/28756">observation</a></strong> of avalanche activity in Hellroaring Creek. </span></p>
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
From obs: "I toured up Blackmore today and saw a lot of sluffing on steep terrain and very wet snow on s terrain. I pushed off a small wet slide that built a good amount of momentum and could've run far if the terrain allowed. I did dig a pit down to the new old snow interface and had no results in an etc."
There has been a dramatic shift from last week's Avalanche Warning and major avalanche cycle to today at Hebgen Lake. Triggering a large avalanche is becoming much less likely. We had ECTXs in both our snowpits. In one (on a NE aspect), the weak layers were unremarkable. In the second (SE aspect), the snowpack was thinner, and we found a couple of layers of facets. Nothing broke in the test, but recent large avalanches in the vicinity lead me to maintain a healthy skepticism. We remain wary because if you find the wrong spot, trigger an avalanche, and get caught, the result could easily be unsurvivable.
If you take that chance, ease into avalanche terrain rather than going for large slopes, choose less wind-loaded slopes that are generally safer, and follow safe travel protocols, only exposing one person at a time to avalanche terrain.
On a non-avalanche related note, while I was glassing Lionhead Ridge for avalanches, I saw what I believe were the markings (mud and debris) from a bear coming out of hibernation. The season is changing—time to carry bear spray. I know, if it's not one thing, it's another.
