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

A single-family residence in Wibaux County generally does not need a state building permit when it lies outside a local government jurisdiction that requires one by ordinance or resolution¹. We could not confirm a local building-code program for rural Wibaux County, so ask the Montana Building Codes Program to verify the parcel before relying on the exemption^4,7. Montana still enforces a uniform state building code for residential and commercial buildings, and covered projects remain within either a certified local program or the state program⁷. Farm and ranch buildings are also exempt from the state building-permit process, but additional local requirements may apply⁴. Before construction, confirm the parcel is outside the Town of Wibaux, since a town ordinance requiring building permits would override the single-family exemption, and ask the Montana Building Codes Program whether the proposed work is exempt⁴. Septic permits and well rules stay with the county health office and the state water-rights office wherever the parcel sits.

The Montana Building Codes Program is the practical first call for a covered project in Wibaux County because cities, counties and towns without certified enforcement programs fall under the state program⁷. Reach the program at (406) 841-2056 or buildingcodes@mt.gov, and use its online portal for an application when a state permit applies⁷. State review begins after the application and plans arrive; the permit issues only after the plans comply and the required fees are paid⁴. A plan-review charge equal to 35% of the building-permit fee applies to state permits⁴. State field staff inspect projects that require a permit⁷. The county has no building department of its own that we could confirm, and septic permits come from the Wibaux County Environmental Health/Sanitarian rather than the state program⁸. For a single-family home that falls within the residential exemption, ask the program to confirm the exemption before relying on the absence of a county building office.

Wibaux County zoning could not be confirmed from an official county ordinance, planning page or zoning map, so do not describe a rural parcel as unrestricted². Montana law allows county commissioners to adopt zoning after adopting a growth policy, but that authority does not establish that Wibaux County has exercised it⁹. The same unresolved point affects setbacks, minimum home size, building height, lot coverage and minimum lot size. We could not locate an official source naming the zoning jurisdictions or ordinances that apply in the county². Ask the Wibaux County Commissioners to confirm the current zoning status for the parcel, and ask the Town of Wibaux separately if the property is inside town limits. A land division can still trigger Montana subdivision sanitation review even when local zoning is unclear: the state reviews covered divisions comprising less than 20 acres and recreational-camping-vehicle or mobile-home parks regardless of parcel size³.

A Wibaux County drainfield requires a permit from the local health department even when Montana DEQ has already issued a Certificate of Subdivision Approval³. Start with Wibaux County Environmental Health/Sanitarian at (406) 796-2481 or wibauxcomm@wibauxcounty.gov⁸. Montana DEQ reviews sanitation for covered subdivisions, including water supply, sewage disposal, solid waste disposal and storm drainage, while the local health department handles the drainfield permit³. Only about 16.6% of Wibaux County soils are rated without severe limitations for a conventional septic drain field, so make the site evaluation and system feasibility an early purchase condition¹⁰. Septic permits for every address in the county, town or not, come through the local sanitarian, while the state handles subdivision sanitation approval³. A lot approved under a no-facilities pathway must obtain sanitation approval before adding facilities that require sewer or water¹¹. A private well is a separate matter: Montana requires a water right for new wells, and a well using 35 gallons per minute or less and no more than 10 acre-feet per year may qualify for the permit exception, with a Notice of Intent filed from January 1, 2026⁶.

Long-term RV occupancy and tiny-home occupancy on private land in Wibaux County could not be confirmed, because no official county occupancy ordinance or explicit statement about zoning coverage was located². Do not use Montana's public-campground limits as the answer for private property; those rules govern public-use sites, not a homesite. Ask the Wibaux County Commissioners about zoning approval for RV occupancy, temporary camping, tiny-home dimensions and setbacks for the exact parcel, then ask Wibaux County Environmental Health/Sanitarian what sanitation approval is needed⁸. Two or more permanent spaces for recreational camping vehicles or mobile homes can bring a parcel within Montana's subdivision framework regardless of parcel size³. A project with facilities requiring sewer or water must also satisfy the applicable sanitation approval before those facilities are developed¹¹.

1. Confirm whether the parcel is in unincorporated Wibaux County or within the Town of Wibaux, because the residential permit exemption does not override a local ordinance requiring a permit¹.
2. Call the Montana Building Codes Program at (406) 841-2056 to confirm whether the proposed work is exempt or requires state plan review⁷.
3. Contact Wibaux County Environmental Health/Sanitarian at (406) 796-2481 before designing or installing a drainfield^3,8.
4. If the parcel is part of a covered land division, verify its Certificate of Subdivision Approval and approved water and wastewater arrangements³.
5. Plan the well: confirm the water-right exception and file the Notice of Intent if the well qualifies⁶.
6. If the driveway meets a Montana state highway, apply to the appropriate Montana Department of Transportation district for an approach permit or right-of-way agreement¹².
7. If the building site lies in a designated Special Flood Hazard Area, obtain the required floodplain-development permit from the local floodplain administrator¹³.

Put septic feasibility first: only about 16.6% of Wibaux County soils are rated without severe limitations for a conventional drain field¹⁰. Water planning also matters in a county receiving about 15.8 inches of annual precipitation and experiencing severe drought in about 14.4% of years¹⁰. About 65% of the land has a slope of 15% or less, but a parcel-level survey is still needed to identify a practical building area¹⁰. Check legal access and determine whether a driveway connects to a county road or a state highway; new or modified state-highway approaches require state authorization¹². Verify flood status with the local floodplain administrator because development within a designated Special Flood Hazard Area requires a permit¹³. For carrying costs, the effective property-tax rate is about 0.7% and the median annual property-tax bill is about $654¹⁰.