PLUS...after looking at the history of an area of interest. Try to figure out, mainly by deduction, was there a house on that ridge? Would troops have crossed here? If the camp was 2 miles that way, where were the picket posts, etc. Sometimes like with me and one of my buddies last week, it was a total bust. Sometimes, we walk onto a very, very old homesite no one knew existed, because it was not on any maps! One of my 16th century hammered coins came from such a spot.