From the Big Sky Ski Patrol:
There was a snowboard triggered avalanche in the Chippewa Ridge area which is adjacent to Wyoming Bowl. The area is easterly facing, open timber with a lot of cliffs and rock outcroppings. 9400 ft. elevation +/-. The slide broke about 50 linear feet below the ridge top and was 250-300 ft. wide, which we had never seen in that area before. The crown was up to 3’ deep. The ridge is only about 200 vertical feet tall and the slide ran to the bottom. R3D2.