Sixth Principal Meridian — PLSS Legal Land Descriptions

The Sixth Principal Meridian is the reference line for Public Land Survey System surveys across Colorado, Kansas, Nebraska, Wyoming, and South Dakota. By land area, it covers more of the continental United States than any other single principal meridian. If you work with legal land descriptions anywhere in the Great Plains or northern Rockies, you will encounter the Sixth Principal Meridian on nearly every document.

Initial Point and Grid Origin

The Sixth Principal Meridian originates at an initial point in north-central Kansas, at approximately 40°00' North latitude, 97°22' West longitude — near the Kansas-Nebraska border. The meridian line runs due north and south from this origin. The associated Sixth Principal Baseline runs east-west. Every township, range, and section in all five covered states is measured north, south, east, or west from this point.

The initial point was established in 1855 under General Land Office Surveyor General John Calhoun. Federal survey crews extended the grid outward over the following four decades, eventually reaching the Rocky Mountain foothills in Colorado and the high plains of Wyoming and South Dakota. The result is an unbroken rectangular grid covering roughly 500 million acres.

States Covered by the Sixth Principal Meridian

Kansas

Kansas is entirely surveyed under the Sixth Principal Meridian. Every legal land description in the state — oil and gas leases in the Hugoton Gas Area, wheat farm parcels in the central plains, feedlot tracts in the southwest, and mineral rights conveyances throughout — references this meridian. Kansas has no competing meridian: if you have a Kansas legal description, it is 6th PM.

A typical Kansas section-level description: Sec 14, T5N, R3W, 6th PM — Section 14, Township 5 North, Range 3 West. An aliquot part description for a 40-acre tract: NENE Sec 22, T5N, R3W, 6th PM.

Nebraska

Nebraska falls entirely within the Sixth Principal Meridian survey. The state's agricultural economy depends on PLSS descriptions for USDA FSA program enrollment, crop insurance filings, irrigation district administration, and rural real estate transactions. Corn, soybean, and beef production regions across the Platte River Valley and the Sandhills all carry descriptions tied to the Sixth Principal.

Colorado

The eastern plains of Colorado — including the Denver-Julesburg Basin oil and gas fields and agricultural land east of the Front Range — are surveyed under the Sixth Principal Meridian. The western portions of the state use other meridians: the New Mexico Principal Meridian covers the southern mountain counties, and the Ute Meridian covers the western slope. See the Colorado PLSS guide for a county-by-county breakdown.

This multi-meridian structure matters for Colorado specifically. Two parcels with identical township, range, and section numbers but different meridians can be many miles apart. A description in Elbert County reads: SENE Sec 22, T3S, R68W, 6th PM. A description in Costilla County for the same numeric address would reference the New Mexico Principal Meridian and land in entirely different terrain.

Wyoming

Most of Wyoming is surveyed from the Sixth Principal Meridian. The state's energy sector — coal, oil, natural gas, and trona mining — generates thousands of PLSS legal descriptions per year through BLM drilling permits, lease filings, and right-of-way applications. Applications for Permit to Drill filed with the BLM Wyoming State Office require an exact PLSS location tied to the correct meridian. A transposed range number delays approval; an incorrect meridian can route the application to the wrong field office entirely.

A Wyoming section description in the Powder River Basin: Sec 6, T44N, R75W, 6th PM.

South Dakota

Most of South Dakota uses the Sixth Principal Meridian. The exception is the Black Hills region, which falls under the Black Hills Meridian. Agricultural operations, tribal land management on reservation boundaries, and hunting and grazing lease descriptions across the central and eastern parts of the state all reference the Sixth Principal. FSA county offices in South Dakota process USDA enrollment filings tied to quarter-section descriptions with the 6th PM reference.

Reading a Sixth Principal Meridian Description

A complete legal land description referencing the Sixth Principal Meridian follows this pattern:

Aliquot part Section Township Range 6th PM

Examples:

• Sec 14, T5N, R3W, 6th PM — Section 14, Township 5 North, Range 3 West (640-acre section, Kansas)
• SENE Sec 22, T3S, R68W, 6th PM — Southeast Quarter of the Northeast Quarter, Section 22, Township 3 South, Range 68 West (40-acre tract, eastern Colorado)
• NENE Sec 6, T44N, R75W, 6th PM — Northeast Quarter of the Northeast Quarter, Section 6, Township 44 North, Range 75 West (40-acre tract, Wyoming)

The "6th PM" suffix is what distinguishes these descriptions from parcels measured under other principal meridians. In Colorado, where three meridians are active, always include the full meridian reference — never assume.

Abbreviated forms you may encounter in BLM records and historical documents: 6th P.M., 6th Prin. Mer., or Sixth P.M. All refer to the same meridian. In modern practice, "6th PM" is standard.

When You Need to Convert a Sixth Principal Meridian Description

The most common scenarios professionals encounter:

Oil and gas permitting: BLM APD forms require latitude and longitude for the well site. The description comes in as a legal notation — PLSS Section-Township-Range. The conversion has to happen before the form is complete.

Crop insurance and FSA filings: USDA program enrollment and crop insurance acreage reports require quarter-section descriptions that match FSA's CLU boundaries. A single transposed digit — T5N R3W versus T5N R4W — moves the filing one township east.

Title work and mineral rights: Landmen clearing title chains in Kansas, Nebraska, and Wyoming trace parcel history through PLSS descriptions spanning decades. The meridian reference anchors every entry in the chain.

GIS and mapping: Loading PLSS descriptions into GIS systems requires latitude and longitude. The 6th PM grid is not a standard geographic projection — descriptions must be converted before they can be plotted.

Converting Sixth Principal Meridian Descriptions

Township America converts Sixth Principal Meridian descriptions to latitude and longitude using BLM CadNSDI source data — the same authoritative dataset federal reviewers use. Enter a description like "SENE Sec 22, T3S, R68W, 6th PM" and receive the centroid coordinates for that 40-acre tract.

For high-volume work — title runs, batch APD filings, or GIS data builds — the batch converter processes hundreds of descriptions in a single upload. Covers all five 6th PM states and all standard aliquot parts down to the quarter-quarter section.

Try it now: Colorado PLSS Converter · Kansas PLSS Converter · Wyoming PLSS Converter · Nebraska PLSS Converter

FAQ

What states use the Sixth Principal Meridian? Colorado (eastern plains), Kansas (entire state), Nebraska (entire state), Wyoming (most of the state), and South Dakota (most of the state, excluding the Black Hills region).

How do I abbreviate the Sixth Principal Meridian in a legal description? Standard forms are "6th PM," "6th P.M.," and "Sixth P.M." All three appear in BLM records, state documents, and historical deeds. In modern practice, "6th PM" is the most common abbreviation.

Can two descriptions have the same township, range, and section under different meridians? Yes — and they describe parcels that may be hundreds of miles apart. This matters most in Colorado, where the Sixth Principal Meridian, New Mexico Principal Meridian, and Ute Meridian are all active. Always confirm the meridian before converting a Colorado description.

What is the difference between the Sixth Principal Meridian and the Fifth Principal Meridian? The Fifth Principal Meridian covers surveys in Iowa, Missouri, Arkansas, Minnesota, and North and South Dakota east of the Missouri River. The Sixth Principal Meridian covers the central plains and northern Rockies states. Each has its own origin point — they are entirely separate survey grids.

Why does Range 68 West appear in Colorado descriptions? The Sixth Principal Meridian's initial point is in north-central Kansas, far to the east of the Colorado plains. Eastern Colorado ranges run into the 60s and 70s West because of how far west the grid extends from its Kansas origin. This is expected — not a data error.