Water Rights & Land Ownership
Roosevelt County is largely the Fort Peck Indian Reservation (Assiniboine and Sioux Tribes), with the Missouri River forming the southern border. Wolf Point is the county seat; Poplar is the Tribal HQ. The Poplar River drains north-to-south through the county into the Missouri. The Fort Peck-Montana Water Compact sets reserved Tribal water rights that are senior to most state-administered priority dates on reservation parcels.
Active state-administered rights pulled live from DNRC WRQS on 2026-06-01. Roosevelt spans three basins: 40Q (Poplar R.), 40R (Big Muddy / NE Missouri), 40S (Lower Missouri side). Fort Peck Tribal compact rights are administered by the Tribes and are not fully reflected in WRQS.
Roosevelt County Watershed Map
Search Roosevelt County water rights
- Water right format:
- 40Q 12345 00 (Poplar) · 40R (Big Muddy) · 40S (Lower Missouri side).
- Primary basins:
- 40Q Poplar R · 40R Big Muddy · 40S Lower Missouri side.
- Fort Peck Compact:
- Federally-reserved Tribal water rights senior to most state priorities on reservation parcels; administered by Fort Peck Tribal Water Resources, not state WRQS.
- International note:
- Poplar R. and Big Muddy Cr. headwaters extend into Saskatchewan — apportionment under Boundary Waters Treaty.
- DNRC regional office:
- Glasgow Regional Office, 406-228-2561.
- Clerk & Recorder:
- Roosevelt County, 406-653-6250.
Irrigated Acres — USDA Census
Roosevelt County reported 12,003 irrigated acres in the 2022 USDA Census of Agriculture, down from 24,263 in 2017 — a change of −12,260 acres (−50.5%). These are acres that actually received irrigation in the census year, not all land equipped for irrigation.
Source: USDA 2022 Census of Agriculture, Table 10 (irrigated land, acres). See the Measuring Montana Moisture overview →
Quick links
Data sources: Montana DNRC, MSL/DOR Cadastral, MBMG GWIC. Fort Peck Tribal compact rights administered separately from state. Informational only.