Roughest---The Bitterroot Mountains (Montana) with a close second being the Bighorn Crags (Idaho).
I find this interesting. I don't have the experience of most, but have spent a lot of time in the Bitterroot and selway hunting elk and consider it what elk hunting is. I consider it hard but am shocked to hear it called the roughest by one who obviously can speak to such things.
Cheers, my legs are burnt and I gotta head east soon. Thanks Montana.