PLSS Map

http://gis.nwcg.gov/giss_2006/job_aids/maps_and_graphics/USA_PLSS_Meridians_map.jpg
This is a Public Land Survey Systems Map (PLSS) that subdivides land in a geographic area, similar to the cadastral map. It generally uses a series of rectangles to subdivide land to show which land is available. This map shows principal areas and base lines across the United States