once a claim is patented it is private land it can't be claimed over. If your looking inan area with private land "old Patents" and public land. Make sure you know the description given for those claims. So, you can plot out where they are on a map. You can't rely on layers put on maps on the internet.
Once a patent has an owner the title is passed down via selling. Though mineral rights can be retained during the first sale or after. But, that patented land is now a "Parcel".
A lot of places were patented and walked awy fro but, they still have an owner.
Without seeing what your actually talking about its hard to explain whats going on with what your looking at.
Clay will probably chime in and explain it better than me.