Montana PLSS Legal Land Description Guide

Montana is the fourth-largest state by area, covering over 147,000 square miles of plains, mountains, and river valleys. Every acre is surveyed under a single principal meridian, making Montana one of the simpler PLSS states to work with — once you know the system. Oil and gas operators in the Bakken play, mining companies in Butte and the Sweetgrass Hills, timber managers across the national forests, and hunters navigating millions of acres of public land all rely on PLSS legal descriptions to identify specific locations.

This guide covers how Montana's PLSS grid works, including the Montana Principal Meridian, section numbering, quarter section notation, and how legal descriptions function across the state's major industries.

The Montana Principal Meridian

The Montana Principal Meridian is the single origin point for all PLSS surveys in the state. Its initial point is located at the junction of the Montana Principal Meridian line (111°39' W longitude) and the Montana Base Line (45°47' N latitude), near the confluence of the Jefferson and Madison rivers southwest of Three Forks in Gallatin County.

From this initial point:

• Townships are numbered North or South. Most Montana land lies north of the base line, so you will primarily see township-north designations (e.g., T20N, T35N). A few townships south of the base line exist near the Idaho and Wyoming borders.
• Ranges are numbered East or West. The meridian line passes through the southwestern part of the state, so ranges west are found in the mountain regions and ranges east extend across the plains to the North Dakota border.

Because Montana uses a single meridian, you do not need to worry about which meridian applies to a given parcel — it is always the Montana Principal Meridian. Legal descriptions sometimes abbreviate it as "M.P.M." or simply "Montana Meridian."

A typical Montana legal description:

NW/4 Section 14, Township 32 North, Range 21 West, Montana Principal Meridian

Shorthand:

NW 14-32N-21W MPM

This identifies a 160-acre tract in the northwest quarter of Section 14, located in western Montana's mountainous terrain.

Section Numbering

Montana follows the standard PLSS serpentine section numbering pattern. Each township (approximately 6 miles by 6 miles) is divided into 36 sections, each roughly one square mile or 640 acres:

+----+----+----+----+----+----+
|  6 |  5 |  4 |  3 |  2 |  1 |
+----+----+----+----+----+----+
|  7 |  8 |  9 | 10 | 11 | 12 |
+----+----+----+----+----+----+
| 18 | 17 | 16 | 15 | 14 | 13 |
+----+----+----+----+----+----+
| 19 | 20 | 21 | 22 | 23 | 24 |
+----+----+----+----+----+----+
| 30 | 29 | 28 | 27 | 26 | 25 |
+----+----+----+----+----+----+
| 31 | 32 | 33 | 34 | 35 | 36 |
+----+----+----+----+----+----+

Section 1 sits in the northeast corner, numbering runs right to left across the top row, left to right across the second row, and continues alternating through all six rows. Section 36 is in the southeast corner.

In Montana's mountainous western half, sections are frequently irregular. Steep terrain, rivers, and lakes create fractional sections and government lots. The BLM survey plats for these townships show the actual boundaries, which may differ significantly from the ideal square-mile grid.

On the eastern plains, sections tend to be more regular, though correction lines along standard parallels still produce fractional sections on the north and west edges of townships.

Quarter Section Subdivisions

Each section divides into four quarter sections, each approximately 160 acres:

• NE — Northeast Quarter
• NW — Northwest Quarter
• SE — Southeast Quarter
• SW — Southwest Quarter

Quarter sections subdivide further into quarter-quarter sections of 40 acres:

NE/4 NW/4 Section 14, T32N, R21W, MPM

This identifies the Northeast Quarter of the Northwest Quarter — a 40-acre parcel. In Montana, 40-acre quarter-quarter descriptions are common in mineral leases, timber sale boundaries, and hunting access agreements.

For reading quarter-quarter descriptions, work from the smallest unit outward: "the NE quarter of the NW quarter of Section 14" means you start with Section 14, find the NW quarter, then find the NE portion of that quarter.

Oil and Gas in Montana

Montana's oil and gas production centers on the eastern side of the state, where the Bakken and Three Forks formations extend south from North Dakota into Richland, Roosevelt, Sheridan, and Daniels counties.

Bakken Play in Eastern Montana

The Bakken formation is thinner and less productive in Montana than in North Dakota's Williston Basin core, but active drilling continues. The Montana Board of Oil and Gas Conservation (BOGC) regulates drilling and requires PLSS locations on every permit application:

SE/4 NE/4 Section 30, T28N, R56E, MPM, Richland County

This is a standard Montana drilling permit location in the Bakken fairway, about 20 miles west of Sidney. The high range-east number (R56E) tells you immediately that this parcel is on the eastern edge of the state, far from the meridian line.

Montana also has older producing fields in the Williston Basin (Cedar Creek Anticline) and the Sweetgrass Arch area north of Great Falls. All use PLSS legal descriptions for well locations, spacing units, and unitization agreements.

Regulatory Filings

The BOGC requires well locations specified to the quarter-quarter section level, plus footage calls from section lines for precise surface and bottomhole locations. A horizontal well drilled in the Bakken might have:

• Surface location: SE/4 NE/4 Section 30, T28N, R56E
• Bottomhole location: NW/4 NW/4 Section 29, T28N, R56E

Both locations are critical for determining mineral ownership, spacing unit assignments, and royalty calculations.

Mining

Montana's mining heritage runs deep — from the Butte copper mines that powered America's electrification to modern gold, platinum, palladium, and talc operations. Mining claims, both patented and unpatented, use PLSS legal descriptions.

Active mining operations file permits with the Montana Department of Environmental Quality (DEQ) using PLSS locations. The Stillwater Mine in Sweet Grass County (the only US source of platinum and palladium) and various gold operations near Helena and in the Little Rocky Mountains all reference specific sections and quarter sections in their operating permits.

Unpatented mining claims on BLM land are located using PLSS descriptions and filed with both the BLM Montana State Office and the relevant county clerk. A lode claim might cover:

SW/4 NW/4 and NW/4 SW/4 Section 22, T5N, R12W, MPM

This describes two adjacent 40-acre tracts (80 acres total) — a common configuration for a lode mining claim straddling a mineral vein.

Historical mining claims from the 19th century, recorded in county deed books and BLM mineral records, reference PLSS descriptions that remain valid today. Researchers tracing mineral rights or mining history need to read these descriptions accurately.

Forestry and Timber

Montana contains major portions of 10 national forests, including the Flathead, Lolo, Helena-Lewis and Clark, Beaverhead-Deerlodge, and Gallatin national forests. The U.S. Forest Service manages timber sales, grazing allotments, and special use permits — all described using PLSS locations.

A timber sale boundary in the Lolo National Forest might be described as:

Sections 15, 16, 21, and 22, T14N, R24W, MPM, Mineral County

This identifies four contiguous sections (approximately 2,560 acres) included in the sale area. Individual harvest units within the sale are further delineated by quarter section.

Montana's state timber lands, managed by the Department of Natural Resources and Conservation (DNRC), also use PLSS descriptions. State trust land sections (primarily Sections 16 and 36 in each township, granted to Montana at statehood) are identified by their PLSS location and managed for revenue generation through timber harvest, grazing leases, and mineral development.

Hunting and Recreation

Montana has over 30 million acres of public land, and hunting is a major part of the state's culture and economy. Montana Fish, Wildlife & Parks (FWP) uses PLSS descriptions in hunting district boundaries, block management area descriptions, and public land access information.

For hunters and recreationists, knowing exactly which section is public land versus private land is essential. Montana's Block Management Program provides public access to private land in specific areas described by PLSS locations. A Block Management Area (BMA) entry might list:

Sections 3, 4, 9, and 10, T18N, R18E, MPM, Fergus County

Hunters checking access near the Missouri River Breaks or the Charles M. Russell National Wildlife Refuge need to verify land ownership section by section. A PLSS converter gives you GPS coordinates to load into a mapping app, so you can confirm which sections are accessible before you leave the truck.

Montana's state trust land sections (16 and 36) are open to public recreation, but adjacent sections may be private. The difference between legal access and trespassing can be a single section line.

Agriculture and Ranching

Montana agriculture — wheat, barley, cattle, hay — operates on a PLSS grid. USDA Farm Service Agency offices use section, township, and range to identify fields for crop insurance, disaster assistance, Conservation Reserve Program (CRP) enrollments, and other farm programs.

A wheat farmer filing a crop insurance claim in Hill County references land as:

E/2 Section 28, T33N, R14E, MPM

The E/2 notation means the "East Half" — the NE and SE quarters combined, totaling 320 acres. FSA ties this description to the producer's acreage records and crop history.

Montana's BLM-managed grazing allotments on the eastern plains also use PLSS descriptions. A grazing permit identifies specific sections and partial sections included in the allotment. Ranchers holding BLM grazing leases need to know their allotment boundaries by section to manage livestock movement and comply with permit terms.

Common Montana Legal Description Formats

Montana legal descriptions appear in several standard formats:

Full legal (deed or lease):

The Northwest Quarter (NW/4) of Section Fourteen (14),
Township Thirty-Two (32) North, Range Twenty-One (21) West
of the Montana Principal Meridian, Missoula County, Montana

BOGC regulatory filing:

NW/4 Sec. 14, T32N, R21W, MPM

BLM format:

T. 32 N., R. 21 W., M.P.M., Sec. 14, NW/4

Shorthand (landman notes):

NW 14-32N-21W

All four formats describe the same 160-acre parcel near Missoula. Township America's PLSS converter accepts all common Montana formats and returns GPS coordinates for the parcel center.

Tips for Working with Montana PLSS

1. One meridian keeps things simple. Every PLSS description in Montana references the Montana Principal Meridian. You will not encounter meridian confusion like in states with multiple meridians.
2. Range numbers tell you east vs. west. Low range numbers (East or West) are near the meridian line in southwestern Montana. High range-east numbers (R50E and above) mean eastern Montana near the North Dakota border. High range-west numbers (R25W and above) indicate the northwestern part of the state.
3. Watch for irregular sections in the mountains. Western Montana's rugged terrain creates many fractional sections and government lots. Never assume standard quarter section boundaries in mountain townships — check the BLM survey plat.
4. Know the state trust sections. Sections 16 and 36 in most Montana townships are state trust land, open to recreation but managed by DNRC. If you are checking hunting access, identify these sections on the grid.
5. Verify Bakken well locations carefully. In eastern Montana's oil fields, a transposed range number moves a well location by 6 miles. On a drilling permit, that can mean the difference between your mineral rights and someone else's. Always convert to GPS coordinates and verify on a map.
6. Use PLSS for public land navigation. Montana's checkerboard ownership (federal, state, private) makes section-level identification critical for legal access. Convert descriptions to GPS coordinates and overlay on a mapping app before heading into the field.

Convert Montana PLSS Descriptions

Whether you are filing a BOGC drilling permit, researching a mining claim, reviewing a timber sale boundary, or planning a hunting trip, accurate PLSS conversion prevents errors and saves time. Township America covers all Montana townships and sections under the Montana Principal Meridian.

Paste a Montana legal description and get GPS coordinates back immediately.

Try the Montana PLSS Converter