For Dall sheep (and caribou, moose, grizzly) check out Widrig Outfitters in the Yukon. I hunted grizzly with Chris Widrig about 35 years ago when he was just getting started. He is a great guide and fun to be with. His "concession" (exclusive hunting area) is 3,500 square miles, the smallest one on the Yukon, if I remember correctly. The area is so remote that during a 10 day hunt, only once did I see evidence of other people on the planet: a jet contrail.