Avalanche observed just west of Cooke City, outside our advisory area, in Yellowstone National Park on 3/4/2021.
From email: "a fresh, slab avalanche across the valley late this afternoon... I think it is fresh from the last 48 hours if not from today. It was on a SE aspect, around 9300'. By the time I noticed it the light was off the slope, but I could tell that the flank was deep, and that the avalanche probably ran on facets/ depth hoar near the ground. It looked to be a couple hundred feet wide, and at least 3-4' deep."