Snowpack and Avalanche Discussion
<p>Dangerous avalanche conditions exist in the mountains south of Bozeman through Cooke City, Big Sky, West Yellowstone, and Island Park. Today's new and wind-drifted snow will keep the snowpack on edge. Enormous avalanches breaking 5-10 feet deep and hundreds to 1000s of feet wide on deeply buried persistent weak layers are possible, and they are almost certainly unsurvivable if they wrap you up in their grasp. Smaller avalanches within the new and wind-drifted snow are likely.</p>
<p>Recent human-triggered avalanches in Cooke City resulted in partial burials on Sheep Mountain (<a href="https://www.mtavalanche.com/node/31377"><strong><span>photos</span></st…;) and multiple close calls on Scotch Bonnet Mountain (<a href="https://www.mtavalanche.com/node/31345"><strong><span>details</span></s…;, <a href="https://www.mtavalanche.com/node/31357"><strong><span>details</span></s…;, <a href="https://www.youtube.com/watch?v=9kyGpQxAs2A"><strong><span>Scotch Bonnet video</span></strong></a>) and Miller Mountain (<a href="https://www.youtube.com/watch?v=BJGckpdQQpQ&list=PLXu5151nmAvSH326z…;, <a href="https://www.mtavalanche.com/images/24/big-avalanche-north-miller-mtn"><…;). Last Thursday, a rider triggered a behemoth avalanche on Henderson Mountain that broke 2000 feet wide and over 10 feet deep in places (<a href="https://www.mtavalanche.com/node/31294"><strong><span>photos, video and details</span></strong></a>). Read about and look at photos of the long list of large human-triggered and natural avalanches on the <a href="https://www.mtavalanche.com/avalanche-activity"><strong><span>avalanche activity log</span></strong></a>.</p>
<p>The frequency of avalanches in the mountains south of Bozeman through Island Park has not equaled Cooke City. However, the magnitude of the slides makes my stomach turn. Yesterday morning, groups reported a fresh avalanche on the north side of Mount Blackmore that ripped apart mature trees after breaking 8 feet deep and hundreds of feet wide <span>(</span><a href="https://www.mtavalanche.com/node/31432"><strong><span>overview video and photos</span></strong></a><span>)</span>. Three avalanches at the head of Beehive Basin broke 3-5 feet deep this weekend, one of which wiped out the skier’s skin track and piled debris 10-15 feet deep (<a href="https://youtu.be/ZaqRmvvNp9c"><strong><span>video</span></strong></a>, <a href="https://www.mtavalanche.com/node/31386"><strong><span>details</span></s…;, <a href="https://www.mtavalanche.com/node/31343"><strong><span>photos and details</span></strong></a>).</p>
<p><span>Execute a conservative travel plan that largely avoids slopes over 30 degrees. If you go onto steeper slopes, select smaller pitches free of terrain traps and at the lower angle end of the spectrum, and be prepared should something go wrong. The danger is CONSIDERABLE. </span></p>
<p>Human-triggered avalanches breaking within recent and wind-drifted snow are possible in the Bridger Range. Last week, two skier-triggered avalanches on Saddle Peak initiated on wind-loaded slopes and broke 1-2’ deep and up to 200’ wide (<a href="https://www.mtavalanche.com/node/31330"><strong><span>details and photos</span></strong></a>). Skiers in the northern Bridger range noted recent natural avalanches that occurred earlier last week (<a href="https://www.mtavalanche.com/node/31418"><strong><span>Bridgers photos</span></strong></a>). Slides do not need to be large to injure or kill backcountry travelers, especially when they are in high-consequence terrain like those on Saddle Peak.</p>
<p>Assess the snowpack for instability before considering terrain steeper than 30 degrees. Choose simple, low-consequence terrain and slopes without previous wind-loading. Carry rescue gear and only expose one person at a time to steep slopes. The avalanche danger is rated MODERATE.</p>
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
Next weekend in Cooke City: Friday at The Antlers at 7 p.m., Free Avalanche Awareness and Current Conditions talk, and Saturday from 10 a.m.-2 p.m. at Round Lake Warming Hut, Free Rescue Practice.