hmm im trying to think of what the steepest inbounds line at whist is, w/b obviously claims the shit out of falsys, but id have to say exhilaration and a few others would be steeper.
as far as backcountry, not too sure, maybe finger chutes on decker? been meaning to ski saddle chute on fissile for a while, hoping to do that this year, that will be the steeps, probably 50-55. summit chute is right next to it, no way ill be skiing that any time soon, or ever, but its can get to be a true 60+ slope.
on the east coast, theres this really fucking random spot about a 1/3 of the way up the superquad at sugarloaf to the lookers left in the woods that runs down to the stream. Steeper than anything ive skied out there, not very long though.