McDonald Creek

Guy and I skinned to Upper McDonald creek in the Flathead Range. We remotely triggered a very large, destructive avalanche from a long distance away on a persistent weak layer developed in January. We travelled cautiously knowing persistent weak layers existed in this area, having remotely triggered a slide in this region a month ago. 

•Varying snow surfaces range from melt/freeze, preserved powder, and wind affected snow at ridgeline. Despite above-freezing temperatures, powder snow was preserved on Northerlies above ~5500'

•Dug two pits on N & NE aspects at upper elevations with propogating results (mid and hard force). These failures occurred on buried persistent weak layers with thick, hard slabs above. 

•Experienced one large collapse on a SE aspect around 7000'
•Remotely triggered a very large (D3) hard slab avalanche ( E - 7000' ) that ran 500 vertical feet, and toppled/snapped trees in the path and runout. Debris was estimated at 10-20'. Crown varied in depth from 3-6ft. 

•Good views of the Flathead Range alpine yielded little natural avalanche activity except for a couple cornice-fall initiated slab avalanches. 

One collapse experienced at 7000' near ridgeline