A PLSS corner is a reference mark that was used to establish part of the U.S. Public Land Survey System (PLSS) that is used for property surveys in portions of the South and West of the U.S. The PLSS system consists of townships, ranges, and sections. Before the government transferred or "patented" the land to private owners, it was surveyed and the boundaries of the sections were established with PLSS corners.

See [http://en.wikipedia.org/wiki/Public_Land_Survey_System PLSS in Wikipedia] for more information.