Been up there many times. 2012 being the most recent. We took up a 650 Kawasaki, 600 Polaris, 400 Suzuki and a 350 Honda. Going across the avalanche was the hard spot. Saw another group of quadders and they turned around and said it was too hard for them. At least they knew there limitations before getting hurt. I would say 1.5 hour hike from where you took that picture, I know the spot. That hillside is always wet and slimey. We came across all female hikers they camped at the plane crash and intended to cross over the divide the next day into BC somewhere.
That trail is a designated ATV trail.