I know someone's done it in scarpa denalis but they had to do a hell of a lot of frontpointing (it may have been here?) Said it paid off big-time for the good skiing while waiting to acclimatize though. (Sorry it's just second-hand knowledge)
Apparently Goran Kropp did if I remember that incident correctly, but details seem to remain hazy on that one. It's funny how climbers make these decisions. Hmm...looks scratched up but not too scratched up...it's a go!
taylor's falls is up north on the st. croix river. dunno about climbing on the mississippi cliffs, a lot of it is unconsolidated sandstone (st. peter formation).