The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
Actually, from a Pennsylvanian perspective this beaver thing belongs on the Wisconsin contingent thread. PA was almost shed of the things (none had been seen in 15 years) when the Game Commission imported a mating pair from WI in 1915.
So, it's WI that has to answer for this...:)