My brother and I put in for the public Ant101 hunt in 2004. When we heard that we drew a tag we assumed that we could go anywhere in the state that was open to that hunt. Well they assigned us each a different ranch, which could have also been anywhere in the state, but it turned out both ranches were in our home county(Unit 16). The next big surprise was that Unit 16 is also known for world class antelope.
If you draw, you'll be assigned to a ranch, and the ranchers are required to give you unrestricted access for hunting. And should make sure you know the boundaries. On the ranch I hunted, the rancher was extremely helpful giving me tips, and scouting, etc.
I had put in and drew for an antelope archery tag about ten years back. I took that hunt about as serious as a Fred Sanford heart attack. I had been wanting to apply again for antelope and last year my brother and I applied and drew(first try and draw for my brother, second try and draw for me). But I have heard that it IS in fact very low draw odds. I've heard a lot about hunters applying for ten or fifteen years before drawing. I'll be applying for the archery hunt this year as I think the odds a little better.