Building permits, zoning and land rules in Roosevelt County, Montana

A single-family home in unincorporated Roosevelt County under state jurisdiction does not need a Montana state building permit¹. Residential buildings with fewer than five dwelling units are also exempt unless they serve transient guests, as are qualifying private garages and storage buildings¹. Farm and ranch buildings under state jurisdiction are exempt from state building permits; that agricultural exemption does not remove septic, floodplain or subdivision requirements¹. Covered non-exempt construction needs a state building permit before work begins, and separate electrical, plumbing or mechanical permits may apply¹. Inside Culbertson, the town requires building permits for all construction, including decks, fences and sheds². Septic permits remain with the Roosevelt County Sanitarian^4,9.

Roosevelt County has no county building department; covered non-exempt projects in state-administered territory go to the Montana Building Codes Program^11,12. Reach the state office at (406) 841-2056 or buildingcodes@mt.gov for project classification and its online application route¹. Submit construction plans and a Building Permit/Plan Review Application; issuance follows written resolution of plan-review comments and payment of fees, with plan review averaging 3 weeks¹. The state calculates the building-permit fee from construction valuation, including finish work, building systems and permanent equipment, and adds a plan-review fee of 35 percent of the building-permit fee¹³. Both fees are due before issuance; certified local governments may use their own fees and valuation methods¹³. State-permitted projects require the permit holder to notify the inspector when work is ready and provide access¹.

Roosevelt County Land Planning reviews projects and processes zoning changes, variances, special-use permits and subdivision applications, but the published description does not establish which unincorporated areas are zoned³. We could not confirm a countywide rural zoning ordinance or countywide setbacks, minimum dwelling size, lot coverage and height limits; ask Land Planning about the specific parcel and use^3,8. Inside Wolf Point, the Public Works Director serves as the city Zoning Administrator; Culbertson also has municipal zoning^6,7. Septic permits remain with the Roosevelt County Sanitarian^4,9. Culbertson’s growth policy says the county has no zoning outside town limits within that planning area, which does not settle zoning elsewhere in Roosevelt County⁶. Covered subdivisions may also need Montana sanitation approval³.

The Roosevelt County Sanitarian reviews and permits onsite wastewater systems and provides installation inspections under state minimum standards and local regulations⁹. A local drainfield permit is required even when a Montana Certificate of Subdivision Approval already exists¹⁴. Only 7.5% of Roosevelt County soils are rated without severe limitations for a conventional septic drain field, so arrange a site evaluation before choosing a house site¹⁵. Reach the Sanitarian at (406) 925 1058⁹. We could not confirm whether alternative off-grid sanitation is allowed; describe the proposed system to the Sanitarian before purchase or design⁹.

We could not confirm a countywide Roosevelt County rule for long-term RV occupancy on private land or a rule specifically governing tiny-home occupancy⁸. Within a regulated flood-hazard area, however, an RV kept on site for more than 180 days or not ready for highway use must meet the residential manufactured-home requirements⁵. New, altered, replacement or substantially improved manufactured homes in those areas must satisfy the floodplain residential-building rules⁵. Ask Land Planning about zoning, subdivision or special-use restrictions and ask the Sanitarian how wastewater must be handled^3,4. A small dwelling may fit the state building-permit exemption, but that does not decide zoning, sanitation or floodplain approval¹.

1. Ask Roosevelt County Land Planning about parcel-specific zoning, subdivision conditions and special-use approvals³.

1. Ask the Montana Building Codes Program whether the proposed structures need state building or trade permits; inside Culbertson, apply to the town for its building permit^1,2.

1. Arrange the Roosevelt County Sanitarian’s site review and obtain the local drainfield permit before installation^4,9.

1. Contact county Disaster and Emergency Services about regulated flood-hazard development; the floodplain application needs a signed form, review fee, scaled plans and other applicable approvals^5,16. Floodplain review includes at least 15 days for public comment, with a decision generally due within 180 days of a correct and complete application⁵.

1. Obtain state authorization for a new or modified state-highway driveway approach¹⁷.

1. For state-permitted construction, resolve plan comments, pay fees and request required inspections¹.

Make septic feasibility a purchase contingency: only 7.5% of Roosevelt County soils are rated without severe limitations for a conventional drain field¹⁵. Check regulated flood-hazard status before development; floodplain approval does not replace other required approvals⁵. For a well, Montana requires a water-use permit above 35 gallons per minute or 10 acre-feet per year; smaller groundwater uses may qualify for an exception¹⁸. Beginning in 2026, the exception requires a Notice of Intent to DNRC before using water, with a $400 filing fee¹⁸. We could not confirm mandatory utility-connection requirements or county-road driveway permitting; ask Land Planning for the responsible office and identify the water provider before closing³. New or modified state-highway approaches require state authorization¹⁷.