Many natural avalanches on Mt Blackmore

Mt Blackmore
Northern Gallatin
Aspect Range

From an observation on 2/16: "My partner and I skied off the north-north east ridge of Mt Blackmore into the Fox Creek drainage and observed five recent, naturally-triggered avalanches from the recent storm. Three D1 avalanches were scattered across the bowl from the north, northeast and north-northeast aspects next to exposed rock-outcroppings but were too small to capture in a photo. A fourth, D3 R3 avalanche occurred at approximately 9200' on the north aspect that appeared to have broken right at the bedrock and slid approximately 200 vertical feet. Crown looked to be up to 6' deep and 600 feet across. The fifth, D3 R4 avalanche occurred at approximately 9400' on the north-northwest facing aspect in a narrow meadow. Crown was approximately 8' deep and 30 feet across (the width of the meadow). There was rapid wind-loading still occurring on the aspects of the two D3 avalanches covering up their slide paths and we observed significant wind-loading and cracking off the northeast ridge line."

From a separate group on 2/16: "Took a walk up near Blackmore today to take a look at a NE facing aspect. We did not ski our objective because we observed active wind loading and saw many recent avalanches.

The first picture is looking at Alex Lowe Peak from the west ridge of Elephant. There were 5 avalanches clearly visible. I highlighted the crowns/debris paths with red.

The second picture is a close up of the avalanche on the ridge between Elephant and Blackmore on a south aspect. This one was the largest and the most fresh. All avalanches appeared to be naturally triggered from wind loading.

We also saw an avalanche looking north from the NE ridge of Elephant over the east ridge of Blackmore. The avalanche was on a south/southeast facing hill and looked like it broke at the ground. It was pretty sizable. We didn't get a picture, but this looks like it would've been visible from the east ridge of Blackmore looking north."

Forecasters visited the area on 2/21/2020: Saw over 15 old avalanches. Estimate an additional 8 that the above groups did not report, so a total of 18+ in the area during the cycle.

Number of slides
Number caught
Number buried
Avalanche Type
Hard slab avalanche
Natural trigger
R size
D size
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
40.0 inches
Vertical Fall
Slab Width
Slab Thickness units
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year