I don't know about other states, but in Missouri, the regulations state clearly that you can't trespass just to retrieve a deer, or any other animal you've shot.

I do some of my hunting on conservation land and it would suck to watch a buck run onto private land and not be able to retrieve it, but landowners have rights and have paid several thousand dollars for their land, not to mention the on going taxes.

Just my 2 cents.