Just found this thread - but, since we have done this - for years and years - here's the truth, and nothing but the truth. Yes, you can use a cabin that's on a claim - it doesn't have to be patented. First, a mining claim (unpatented) gives you the mineral rights - but, it also transfers SOME surface rights and is considered real real estate. Now, here's the hitch in the giddyup. The cabin (and whatever surface you are allowed) ALL has to be incidental to the mining. A tool shed, a living area -WHILE YOU ARE ACTIVELY MINING - vegetation and trees, are all acceptable (at least until they dump the 1872 mining law). It also gives you legal access, and allows you to restrict others from setting foot on the active workings (though, be sure to mark your active site). We lived on our claim, built a cabin, etc. All legal. When we had to pack up to take care of my mother while she died of cancer, they actually stole the cabin. They winched it onto a flatbed, and drove away with it. (including its contents). However, when we go back, they don't stop us at all from re-setting up. I can also tell you from personal experience - if someone trespasses on your active area, and you call the police - they WILL arrest them, and you can collect damages. That also goes for the jerks with metal detectors (though I detect myself), if you are metal detecting on someone's claim, you CAN go to jail. And telling the officers that you are looking for relics and/or brass won't get them out of it, either. So, if you have an unpatented claim, you still have rights.
Mrs. O
PS: A patented mine is private real estate.