Quick report
We rode a similar line to our first lap, riders left in the trees of the east face. Halfway down I trended right on the treed shoulder and while riding I looked over toward the east face to see if there were any tracks on it. Looking up the hill I saw an avalanche coming down the slope above and to my right. . I assumed someone in a different group kicked it off while riding the east face. The slide passed me to my right about 200 hundred feet away moving fast. I was also going fast, 35mph, and increased my speed while riding next to the avi. When the slide stopped my group went into search mode to see if anyone was under the slide. . Considering how far ahead of the slide I was, I am not sure if I remote triggered it or there was randomly a natural avalanche. I assume the former, but who knows? Looking closer I believe the slide did not come from the east face, but a steep roll on the corner of it. See photos attached.