This was the first slide I saw triggered by snowmobiles in White Pine today. Probably about 400ft off the ridge line. Heard and saw the biler heading up the slope, looked like he got the sled turned around and avoided the debris, but did not hear his machine running after the slide. There was a whole group of snowmobiles in the same area and they continued to high mark after the slide so I assume the trigger of the first slide was OK.