Woody is right about charging for "access" to a location claim being illegal as stated for accessing a claim, that's just not how you get "use" of a claim.
You could however lease a claim (for money or non-monetary) which is just a personal agrrangement between you and the claim owner. Some folks do lease claims for a percentage of what's extracted. But remember that the claim owner already owns the minerals on his/her claim when and if you decide to negotiate use/lease of a claim in this fashion. I've seen folks make offers of very little % cut to the claim owner for their desired prospecting on the claim. If they already own the minerals, don't try to be greedy on the cut and you'll have a better chance of someone striking a deal with ya'.
For large scale or full time operations under lease agreements, there is normally a fair cash fee up front as well as % of all extracted minerals that goes to the claim owner normally.
You can also do an exchange for reports on finds like we have already set up on the free non monetary claim lease. Good for a short prospecting trip to do some sampling on a claim.
You can print if off and then add/amend to it if needed but gives one a basic start for a lease agreement. This works great for a non-exclusive, non-monetary agreement that shows in the field you do in fact have permission to "prospect" the claim from the owner for a defined time period.....2 days, weeks or months etc as agreed with the owner.
Most claim owners will be glad to let you sample their claim and keep your finds (barring the spectacular) and are happy to know if you found something, where it was and how deep etc. If you do find the "spectacular" find....remember again, the minerals are already theirs in the ground, that's why they are "claimed".
We have the claim lease posted here at this page in the valuable references section of the forum
Mining claim leaseCheck it out if needed in the future.