This system is used for the survey and description of property that is or may have been subject to the jurisdiction of the U.S. Land Office.
A fixed point is established as a basis for the survey of a particular area of land. This point is described by its longitude and latitude, that is, by the intersection of a true north-south line (true meridian) and a true east-west line (baseline). In Southern California, this basis or point for such surveys is called the "San Bernardino Base Line and Meridian." It is located on San Bernardino Mountain in San Bernardino County.
The survey is made from the baseline and meridian, running both north-south and east-west. Points are established at six-mile intervals in the aforementioned directions, with lines drawn at these points east-west, parallel to the baseline, and north-south, parallel to the meridian.
