With the Reservation permit you can hunt upland game, waterfowl, bunnies, etc... I always buy mine at Bi-mart. I don't know of anyone hunting this unit recently, but I know in the past some very large elk have been killed up there. There really isn't a definite southern boundary(that I know of). It is basically an imaginary line from reservation creek to coyote rocks I believe. I think it is quite a drive to get up in there, but I have never done it, just looking at the maps.
You could always camp on the Cowiche side and drive over into the other unit if you wanted to camp.