Cam Bacon wrote a book on rockhounding. The following day sees parties heading out in several directions. Some are looking for 'easy' stuff at well known areas. Others are trying their luck in new territory, or attempting to find a path to some ancient outcrop. Roads disappear, of course.
Forests grow up.
Even lakes appear or disappear. And agriculture spreads across what was previously wild country. It all adds a challenge to the rockhound. A couple of us are trying to figure out where an old copper mine must be. The records usually include some sort of site description, or even a map.