Haven't hunted 20 but did hunt 21 a few years back. West out of Kaycee is a small walk-in area that is connected to plenty of BLM land to keep your feet busy. I believe it is on the Brock rd. There seems to be a few more spots where this road touches blm. I will be hunting A22 on a second choice. After looking for private land in 21 & 22 (which I have hunted 3 other times) it appears that outfitters have acquired rights on most private lands. You probably will get the scoop from others you meet while hunting there. Good chance the other hunters will give you good leads on the does.
Good luck on your hunt,
Randy