Flathead Range & Glacier NP

Dangerous avalanche conditions still exist thanks to weak layers buried 2-4' below the surface. These are the same layers responsible for a rash of recently triggered avalanches. Swirling winds have and continue to form slabs on most aspects.  Utilize terrain to minimize your risk by choosing low-angle slopes free of rollovers. Avoid recreating above terrain traps where debris can pile up deep. Dense snow is a sign of a slab and alerts you to seek sheltered terrain.

For the past five days, the avalanche danger was rated HIGH in the Swan Range, the Flathead Range, and Glacier Park. Having the hazard elevated for this length of time is almost unheard of in NW Montana. It is not unusual to have several periods with a HIGH rating each season. But these generally only last 1-3 days and are almost always associated with large precipitation events like an Atmospheric River. Perhaps our snowpack is carrying on where 2020 left off - vastly different and nearly unrecognizable compared to years past.

Our Persistent Slab problem is responsible for nine consecutive days of intentionally, remotely, and accidentally triggered slides through Saturday. Sunday was quiet, avalanche-wise, as frigid conditions, an Avalanche Warning, and the super spreader athletic event limited the number of potential triggers in the backcountry. On Monday, Guy and I visited the Swan Range. Despite receiving 1.5” of water Saturday, the snowpack offered little feedback, such as shooting cracks or collapses (whumphing). With up to 6” of cold smoke quality new snow capping another foot or more of recent snow, the riding looked great. We gazed down one of our favorite runs, a north-facing slope with widely spaced old-growth, and remarked that it could be the run of the year. Fortunately, we had dug into the snowpack and noted a weak layer buried above the 1/13 crust. Although our snowpack test results weren’t alarming, we did not care for the clean shear planes we identified. We followed the skinner back to the sleds knowing that we had plenty of great riding the second half of this winter. A rider in the southern Whitefish Range also noted no signs of instability in his travels. Despite this, he chose terrain that minimized his exposure to hazards while watching others do the exact opposite.

We have dropped the danger down a notch today, but that doesn’t mean we can let our guard down. The snowpack may not be offering obvious clues of instability, but weak layers still exist and can ruin your day. Recent snowfall has buried these layers deeper in the pack, and therefore they are not as susceptible to our weight. That is until you find the “sour spot” where you can impact the layers of concern. These may be where the layers are closer to the surface, where stress is concentrated (convexities), or recently loaded areas at their tipping point.

On Saturday, a group of snowmobilers was caught, carried, and one killed. The most up to date information on this accident are found here. We will update you as more information becomes available. Our condolences go out to all of the friends and family of the victims of these tragic accidents. We thank the rescuers who accept large amounts of risk during these events.