A friend of mine used to operate the Temperance Creek Ranch in Hell's Canyon. Jet Boat or fly in, and the mule from there on. Don't know if the new owners are giving a quality experience, but the one time I had a drop camp there it was outstanding. We got mid-ways up the canyon wall and then used ridge lines and trails to get on the animals. Good population in this area. I'm not a hunting outfitter in Hell's Canyon, but I am a whitewater rafting outfitter there and see the elk constantly. This is an OTC tag for archery.
I have some friends that have used Steens Wilderness Adventures. They were taken into the Eagle Cap Wilderness in the Imnaha unit. Saw lots of elk, took an average 6x6 or heard the mountain climbs to get to the elk were brutal.