PLSS Map

http://www.nationalatlas.gov/articles/boundaries/a_plss.html

PLSS maps facilitate ownership. The map will have an initial point, followed by an east-west line called a base line and a north-south line, called a principal meridian, which extend through the inital point. It contains horizontal lines at six-mile intervals that parallel the base line and establish townships. Vertical lines at six-mile intervals that parallel the principal meridian establish ranges.