Sixth Principal Meridian

The Sixth Principal Meridian is the single most widely used reference line in the entire Public Land Survey System. Established in 1855, it serves as the north-south baseline for surveys across five states: Colorado, Kansas, Nebraska, Wyoming, and South Dakota. If you work with legal land descriptions anywhere in the central Great Plains or the northern Rockies, you will encounter the Sixth Principal Meridian regularly.

Initial Point

The Sixth Principal Meridian originates at an initial point located at approximately 40°00' North latitude and 97°22' West longitude, situated in north-central Kansas near the Nebraska border. From this point, the meridian line runs due north and south, while the associated baseline extends east and west. Together, these two lines form the grid from which all townships, ranges, and sections in the five covered states are measured.

The choice of this location was deliberate. By the mid-1850s, settlement pressure was pushing westward across the Kansas and Nebraska territories, and the federal government needed a survey framework to support the Homestead Act and the disposition of public lands. Surveyor General John Calhoun oversaw the establishment of the initial point, and field crews fanned out from there to begin subdividing millions of acres.

States Covered

Kansas

Kansas is entirely surveyed under the Sixth Principal Meridian. Every legal land description in the state references this meridian, from the eastern farmland along the Missouri River to the short-grass prairie of the High Plains. Oil and gas activity in south-central Kansas, wheat farming across the central corridor, and ranching operations in the Flint Hills all rely on PLSS descriptions tied to the Sixth Principal Meridian.

Nebraska

Like Kansas, Nebraska falls entirely within the Sixth Principal Meridian survey. The state's agricultural economy, one of the largest in the country, depends heavily on precise land descriptions for crop insurance filings, USDA FSA program enrollment, and irrigation district management. A typical legal description for a Nebraska farm parcel might read: NE 14-5N-3W 6th PM — meaning the Northeast Quarter of Section 14, Township 5 North, Range 3 West, Sixth Principal Meridian.

Colorado

Colorado's eastern plains are surveyed under the Sixth Principal Meridian, while the mountain and western portions fall under other meridians (the New Mexico Principal Meridian and the Ute Meridian). Oil and gas operations in the Denver-Julesburg Basin, agricultural parcels on the eastern plains, and rural property transactions across the Front Range corridor all reference the Sixth Principal Meridian.

Wyoming

Most of Wyoming is surveyed from the Sixth Principal Meridian. The state's mineral extraction industry, including coal, oil, natural gas, and trona mining, generates thousands of legal land descriptions annually. Drilling permits filed with the Wyoming Oil and Gas Conservation Commission require exact PLSS locations, and a transposed range or township number can delay an Application for Permit to Drill.

South Dakota

South Dakota uses the Sixth Principal Meridian for most of the state, with the exception of the Black Hills region, which is surveyed from the Black Hills Meridian. Agricultural operations, tribal land management, and hunting lease descriptions across the central and eastern parts of the state all reference the Sixth Principal Meridian.

Format Examples

Legal land descriptions referencing the Sixth Principal Meridian typically follow this pattern:

• NE 14-5N-3W 6th PM — Northeast Quarter, Section 14, Township 5 North, Range 3 West
• SW 22-9N-15W 6th PM — Southwest Quarter, Section 22, Township 9 North, Range 15 West
• NWNE 8-12N-7E 6th PM — Northwest Quarter of the Northeast Quarter, Section 8, Township 12 North, Range 7 East (a 40-acre tract)

The "6th PM" suffix distinguishes these descriptions from parcels measured under other principal meridians. In states like Colorado, where more than one meridian applies, including the meridian reference is essential to avoid ambiguity.

Why It Matters

The Sixth Principal Meridian covers more land area than any other single principal meridian in the PLSS. Anyone working with rural land records, mineral rights, agricultural programs, or public land management across these five states will encounter it daily. Understanding which meridian governs a particular parcel is the first step in correctly interpreting and converting a PLSS description to GPS coordinates.

A common error is omitting the meridian reference when converting coordinates. Two parcels with the same township, range, and section numbers but different principal meridians can be hundreds of miles apart. Always confirm the governing meridian before converting.

Historical Context

The Sixth Principal Meridian was one of the later meridians established in the PLSS. By 1855, earlier meridians (the First through Fifth) had already organized surveys across Ohio, Indiana, Illinois, and other eastern public-land states. The rapid westward expansion following the Kansas-Nebraska Act of 1854 created urgent demand for a new meridian to anchor surveys across the central territories.

Field surveys extended from the initial point over the following decades, eventually reaching the Rocky Mountains in Colorado and the northern plains of Wyoming and South Dakota. The resulting grid remains the legal framework for land ownership in all five states to this day.

Converting Sixth Principal Meridian Descriptions

If you have a legal land description referencing the Sixth Principal Meridian and need GPS coordinates, Township America can convert it instantly. Paste in a description like "NE 14-5N-3W 6th PM" and get the latitude and longitude for that parcel. For large volumes, use the batch converter to process hundreds or thousands of descriptions at once.