I'm not sure that you can ever create a legal contract, with a government, that binds the hands of a "future government". You can do it in the private sector but not in government.
Now, if you owned the land, you could sell me, or sell the government an "easement" or a "right to access" that would become part of a deed, but I don't think it can go the other direction, if the government owns the land. The best you could do would be a "lease" for x number of years.
I could be completely wrong however.
For me, this issue goes beyond hunting access. I'm as concerned over the other users of the public lands as I am with my personal use for hunting and fishing. I am a diehard believer in the multiple use concept, and want these lands to remain available to live stockmen, miners, loggers, back packers, atvs users, and picnic'ers from the city. I'm a diehard supporter of requiring all working Americans to contribute to and have the use of our current public lands. Once they become private property, I'm out and so are miilions of others.
Why should all Americans pay for what only some use? For the same reason I pay taxes for municipal golf courses, swimming pools, race tracks, sports arenas, schools, fire departments, etc. etc. I use none of those things but I pay for them because they make us who we are as a people, and they make communities more than labor camps and feudal system of Europe before freedom broke out. We're all in this together and we all pay for everything, whether we use it or not. Not unlike an irrigation company and the canal systems or Inter-State highways.
Hell, if I was going to really tell you how I feel, I'd tell you I think the Federal government should be required to purchase large tracts of land all the States, (from willing sellers, of course) especially those in the East, the Mid-West and the South and turn them into multiple use lands, so all Americans would have public lands access in every State, not just here in the Western States. Having access to thousand upon thousands of acres to use responsibly, at your own discretion, is a priceless freedom no other peoples in this world enjoy and it should be part of every State and it must never be taken away from our citizens. That's how over the edge I am about this public land business. It's no different than sharing in the cost of a school to educate our children, not one bit different.
I'd rather pay more personal income and or property taxes, and receive fewer government services, in order to be able to make sure that Stoney can graze his live stock on our ground, Big John can mine coal on our ground, Kelly can log timber on our ground, and you and I can hunt these deer were trying to raise on our ground, under the multiple use program, than to take any chance on cutting a better deal with State government.
Here's an novel idea, elect some Federal Legislators that will fix the damn Federal mess, including the U.S.F.S., BLM, EPA, and all these screwed up Federal Bureaucracies and get Federal public lands administration doing with it's supposed to do. Lets fix the problem rather trade it off to some other group of State Bureaucrats that have already proven they will absolutely make it worse.