It's hard to say for sure when it is so wet -- really need to let it dry so you can study the distribution of tomentum on rhizines and veins. But I would guess P. membranacea for this. P. cinnamomea usually grows in rather flat array of lobes.
I think that cinnamomea is keyed in McCune and Geiser, but doesn't get full page treatment. I think there will be lots of Idaho sites once people learn the species and start looking for it.
-Bruce