Avalanche: Hillyard Canyon

Observer Name
Ryan Larsen
Observation Date
Friday, January 19, 2024
Avalanche Date
Friday, January 19, 2024
Region
Logan » Southeast Idaho » Cub River » Hillyard Canyon
Location Name or Route
Hillyard Canyon
Elevation
7,100'
Aspect
West
Slope Angle
38°
Trigger
Snowcat
Trigger: additional info
Remotely Triggered
Avalanche Type
Soft Slab
Avalanche Problem
Persistent Weak Layer
Weak Layer
Facets
Depth
2'
Width
50'
Vertical
100'
Snow Profile Comments
We checked out the avalanche and surrounding slopes in Hillyard Canyon on Tuesday, 1-30-24. Here is a crown profile. We noted a pronounced increase in snow stability in the time since the avalanche occurred...(11 days ago)
Comments
First: A rider reported that a couple of natural avalanches had hit and crossed the groomed trail in Hillyard Canyon on Sunday, January 14, the same day the UAC issued an Avalanche Warning and forecasted Extreme danger in the area.
On the Idaho Tri-County Snowmobile Program's Facebook page, this is from Chuck Hulse: "Thanks for the update. Cub River was trash today (wasn’t much better on Thursday). Obliterated is a good word for it. As a heads up, Hillyard slid in 2 places at some point from Thursday to today. The 1st one didn’t do much, but crossing the second one is a hazard. Between that and the current trail conditions, I can’t imagine trying to get a broken sled (or worse an injured person) down and out to the trucks. Yikes!"
Then: On Friday, January 19, the trail groomer triggered a couple of avalanches while driving the snowcat down Hillyard Canyon. The first one was pretty small, but it was a red flag, and the operator turned the snowcat around. The second one was quite large, barely missing the snowcat, and it crossed and buried the road with a good-sized pile of debris up to 8 feet deep. The snowcat operator wisely ceased grooming operations after the large avalanche.
Comments
This is from a January 20 Facebook post by Idaho Tri-County Snowmobile Program,
"Friday the cat made a long haul from Copenhagen parking lot to the Birch Creek lot and back to Paris, while the small cat worked on opening Hilliard Canyon. That effort was called off when we triggered a two foot slab avalanche in the second slide area, and had to dig out. As such, the trail was groomed from Green Canyon to the top of Hilliard, but the lower end of the Cub River trail has not been groomed. We apologize, as we know how popular this trail is, but until conditions permit, we will not be working in that area. Please consider accessing different riding areas until the avalanche danger decreases in Hilliard Canyon."
This is from Ryan; "It doesn’t look like much from a picture, but rather disconcerting to be below. I’m probably 15 feet above the actual road cutting out the original slide."
Coordinates