Have you checked with the game wardens on Pendleton itself about hunting there? They have very good deer hunting, and I have seen plenty of coyotes there. Just not sure if they allow you to shoot the yotes too.
Also, look out for the buffalo, and don't even think about shooting one. Fun to watch though.
If you cannot find a place on base, get a map of the Cleveland National Forest. Closest access for you would probably be out Route 76 to Palomar mountain. It's probably a 45-60 minute drive until you hit public land there.
Let me know if you have any other qeustions. I know a couple of the base wardens, so I could try to find out about yotes on base.
If you want to properly preserve velvet antlers, you will have to inject & brush them with formaldehyde or some of the new less toxic chemicals (4 in 1 solution works great as does Knobloch's antler in velvet tan) as its easier to use however, both will work.
First, using rubber gloves take a razor blade and make small incisions at the tips of all points about 1/8". Next hang the antlers upside down, allowing the blood to drain. Starting at the bases inject the solution into the...