Aside from googling for sample lease contracts, I don't know. One thing you may try is to look for local landowners and timber companies that do lease their land, and see if you can get a copy of their contracts.
I have a copy of a book called Hunt Club Management Guide by Wayne Fears, and on pages 130-131 there is a "Sample Land Lease Agreement." I got my copy of the book a couple of years ago on eBay, and there's a copy there now with a starting bid of $3.99. Or, you can get it on Amazon for $13.70.
Beyond that, I'll say "welcome" to the D&DH forums. I hope you get the answer to this question and many more in the future.
Steve

