Public Land Survey System (PLSS) explained
The Public Land Survey System is the US township-and-range grid used across 30+ states and 37 principal meridians. A PLSS description reads section, township, range, meridian, state.
Township, range and section
Townships are referenced north or south of a baseline and east or west of a principal meridian. Each township holds 36 sections of about one square mile (640 acres).
T3S R1W Section 34 means section 34 of township 3 south, range 1 west of the governing meridian.
Frequently asked questions
How many principal meridians does the PLSS use?
The BLM recognises 37 named principal meridians across the 30-plus PLSS states. The same township and range repeat off each, so the meridian is essential.
How are PLSS sections numbered?
A township's 36 sections are numbered in a back-and-forth pattern, starting at section 1 in the north-east corner and ending at section 36 in the south-east.
Last reviewed June 2026. General information about survey systems — not legal, title, or survey advice.
Sources: US BLM — Cadastral Survey (PLSS), BLM / GLO — Principal Meridians and Base Lines (map).