A long time ago in a galaxy far, far, away (specifically Arizona backcountry in the 1950s) cabins were left unlocked. It was explained to me, and demonstrated, that you were welcome to use the cabin and its dry firewood ( as well as any food left, if necessary) and leave things neat, paying particular attention to stockpiling dry kindling next to the stove for the next person.

A regular feature of most of these cabins was a loaded Winchester 30-30 under the mattress. Somehow I don't think things operate in this fashion anymore.