Looks like Kinney Lake or the flats just north of the lake -- the "low" walk through the forest.
Pretty wide flood plains along sections of the route.
Yes, and once you descend from Whitehorn there is really no other way across. This is why they had to helicopter evac hikers 'stranded' above.
It's quite crazy summer here btw, historic heat wave that caused all this melting. I am frankly surprised there are still no wildfires (except around Lytton, BC)