Principal meridian

A Principal Meridian is a fundamental reference line used in the Public Land Survey System (PLSS) in the United States. The PLSS is a method for surveying and categorizing land to facilitate property ownership and land management. The Principal Meridian serves as a starting point for defining the township and range system used in the PLSS. Each Principal Meridian is associated with a specific geographic area and is typically accompanied by a Baseline, which runs perpendicular to it.