The Land Ordinance of 1785 devised a system base lines and meridian lines using to survey the western lands outside the initial 13 colonies. Base lines run east/west and meridian lines run north/south. CSU,Chico is located on the Mt. Diablo Meridian and Base lines. Along these lines the land was divide into 6 square mile blocks, called "Townships". Each Township is given a identifying number, according to where it falls. The east/west numbers are identified by the term "Range" and the north/south numbers are identified by the term "Township". Chico is located in Township 23 north, Range 1 East, Mt. Diablo Meridian. Each township is divided into 36 square-mile parcels of 640 acres, called "Sections". Every section is numbered from 1 to 36, depending upon its position within the township. A section can be further divided into halves, quarters, etc. 

Many legal property descriptions are identified by the township/range system, i.e. "North West 1/4, Section 34, Township 1 South-Range 3 East, Mt. Diablo Meridian". To locate a land parcel from its legal description, the trick is to read backwards-beginning with the principal meridian line and working back through the township and range, the section, and then the fractional section.