I am partners with our chapter president on two claims that are GPAA in our area. Walter notified us that they had been closed to to paperwork issues. We managed to get them refiled and saved for the Association.
I also am in partnership with a chapter member on our own 40 acre claim. Likewise, we find campers and trash the biggest issue.
The GPAA claims do tend to get more use as they are on a paved road, and we do check to see if users are members if we see prospecting equipment in the campsites. Depending on the user's attitudes and what time they are there, we might let them finish the day, and invite them to chapter meetings. It is also well understood that it is a one time exception, and if we find them there again and not members they will be turned in to the local law enforcement agency.
The other GPAA claim in our area is not owned by us, so we can't extend that offer there, but we tell them where the public area is, and still invite them to a meeting. We have gotten a couple of members by those actions.
We have adopted all three claims, so are up there often checking for use, damage, litter, etc.