Northern Gallatin

Natural cornice fall nearly missed skiers, near Abiathar

Abiathar Peak
Out of Advisory Area
Code
C-N-R2-D2
Elevation
9500
Aspect
N
Latitude
44.97560
Longitude
-110.03100
Notes

From email: "My partners and I were booting up a couloir near abiathar and a large cornice fell and landed shortly below us in our bootpack. Spooked the hell out of us. We acknowledged the danger of those cornices before booting up, decided that it was probably safe due to relatively low winds and cool temps, and decided to go for it. In hindsight, we wonder if it was much warmer on the ridge near the cornice (we were in the shade), maybe we underestimated the ridgetop winds, or maybe we just got unlucky.

The cornice broke up a bit on some rocks before landing in our couloir, but there still vehicle sized chunks raining down. If we had been 5 minutes slower on the ascent we may have been killed."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Cornice fall
Trigger
Natural trigger
R size
2
D size
2
Problem Type
Cornice Fall
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Lewis creek

Date
Activity
Snowboarding

Went for a hike on a ridge line between Lewis creek and mill for hyalite creek. Saw the avalanche on a south/south east facing aspect around 9500’. I didn’t see how far it ran, but last year it broke loose and took out a lot of trees(video). Hard to tell how deep it broke but it broke pretty wide.

Region
Northern Gallatin
Observer Name
Elton

Alex Lowe Peak

Date
Activity
Skiing

We skied the Y Couloir on Alex Lowe Peak and gained the summit via the southwest ridge. The recent snow felt more consolidated but remained stable on both the ascent and descent. We were able to break off a small cornice onto a northern aspect (approximately 4ft long, 3ft high and 3ft in width) of the southwest ridge of Alex Lowe, and the resulting collapse did not trigger any significant sluff or failure of the slope below. The recent snow sluffed more readily as it was baked by the sun during the ascent, on the eastern aspect of the ridge. A ski cut in the couloir did not trigger significant sluff, but the snow was much more dense, throughout the entire couloir, than in days prior on similar aspects.

Region
Northern Gallatin
Location (from list)
Alex Lowe Peak
Observer Name
Erich Schreier

Mt. Bole

Date
Activity
Skiing

Recent snow was sluffing on the North aspect of Palace Butte. Our snowpit on the east ridge of Mt Bole revealed a mostly cohesive slab with a ECTN 28 @ 55cm (The total HS was recorded as 325cm, but the pit was dug only to 150cm deep), and great caution was taken in selecting an approach and descent to avoid shallow spots in the snowpack. The new snow did not sluff during our descent of the east ridge of Mt Bole. We triggered two very small, wet loose slides on southern aspects below Mt Bole and Palace Butte during our return.

Region
Northern Gallatin
Location (from list)
Mt. Bole
Observer Name
Erich Schreier