I was skiing in the Cerise Creek drainage this weekend and observed a large natural avalanche worth noting. The East ridge of Matier above the Anniversary Glacier has avalanched and has run the full length of the valley below the glacier to end approximately 500 meters beyond the toe of the moraines. Debris has crossed Cerise Creek and removed a large swath of the 2nd generation trees on the east side of the creek, then turned the corner and ran down Cerise creek for another 100 meters. At least 300-400 meters of the standard approach to Keith's Hut is under 1 to 3+ meters of debris, including about a 200 meter section of Cerise Creek. Limited observations of the fracture line show it right at ridge top and it appears to be 3-4 meters in depth, possibly triggered by cornice failure during the recent high winds. There also appears to be a significant fracture line and avalanche on the moraine/boulder slopes underneath Joffre, most likely triggered by the impact of the first avalanche off of the East Ridge of Matier. I could not see the middle steeper section of the Anniversary to see if it had slid as well.
I was in the parking lot at 0930 on Saturday Jan. 5th and heard a large event, but with poor visibility could not be sure if it was a large wind gust or an avalanche. When we reached the debris at noon there were a large amount of branches on the snow surface with little snow cover despite heavy snowfall, so I am fairly certain it ran at around 0930 that morning. Luckily there were no people on the approach at the time, though it is a very sobering sight to see such a commonly traveled route under so much debris. A good reminder to always question your choice of route, and what you are exposed to at that time, regardless of how "common" the route is.
Brian Jones
Mountain Guide