Cooke City

Recent large avalanches, continued snowfall, and very strong winds mean VERY DANGEROUS AVALANCHE CONDITIONS EXIST. Both natural and human triggered are likely today. Stay far away from any steep slope because avalanches may run far into flat terrain. Be hyper-vigilant about where you’re traveling because avoiding avalanche runout zones is not easy near Cooke City. People have died in avalanches on the groomed road to Daisy Pass.

Avalanches have been happening throughout much of the forecast areas over the last 4 days. Most being persistent slab avalanches breaking on old faceted snow from October and late November. Yesterday a local snow safety professional said “I cannot remember a season where we went so quickly from being unable to travel around the mountain due to almost no snow, to having full coverage and running destructive avalanches all over the upper mountain. It was a spooky whiplash.”

Over the last 2 days, there have been 19 avalanches reported in the backcountry. See them on our new avalanches observations page HERE. Some have been large, some smaller, some natural, and some remotely triggered. Most have broken near the ground on old faceted snow from October and late November. If avalanches don’t break on that layer today, you’ll certainly find freshly formed wind slabs that will avalanche.

Near Cooke City, more snow overnight (5 inches), more coming today, and high winds means that avalanches are likely today. Big slopes will produce big avalanches that may run far into flat terrain below. Stay far away from any slope steeper than 30 degrees. Notable big avalanches include one on Miller Mountain, Mt Henderson, and Mt Republic - the Fin. The avalanche danger today is HIGH on all slopes.

In the northern Gallatin and Madison Ranges, and the Bridger Range, avalanches in Hyalite Canyon south of Bozeman, Buck Ridge and Beehive Basin near Big Sky, and in the Bridger Range indicate an unstable snowpack as well. Additionally ski patrollers at Big Sky Resort (where the snowpack resembles backcountry conditions) have triggered many avalanches over the last two days. The avalanche danger is HIGH at upper elevations and CONSIDERABLE at mid and lower elevations.

Further south in the southern Gallatin and Madison Ranges, Lionhead area, and Island Park area, we haven’t received any observations because there haven’t been too many people out riding. Similar conditions exist but the snowpack is generally thinner as less snow has fallen since Thanksgiving. The avalanche danger is CONSIDERABLE at mid and upper elevations and MODERATE at low elevations.

WHAT TO DO? Right now the snowpack is growing quickly and experiencing rapid change. Weak layers of facets near the ground on many slopes are under a lot of stress and causing many of the recent avalanches. The simple answer is to avoid all avalanche terrain for now and let the snowpack do its thing. Don’t mess with it. Seek out slopes less than 30 degrees in steepness with nothing steeper above and sheltered from the wind.