Wow I'm jealous! I've been back in some of that area hiking and bird hunting and seen some sheep, dreamed of some day being able to hunt that high zone.
If I were to do this hunt, I would start scouting via California Creek and focus my efforts around Bird Peak (not to be confused with Bird Ridge which is about 6 miles to the east).
Obviously, there's a population of sheep around McHugh and Indian House (saw a full curl right off the Highway by McHugh today), but I'm not sure that band ever enters the huntable terrain of DS138. For instance, do those sheep ever get to Williwaw? I don't know. I *think* the eastern zone gets less human interference and may hold happier sheep.