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

A single-family residence in Carter County does not require a building permit unless a local government requires one by ordinance or resolution¹. Carter County's official department listing has no county building or inspection department, while the Town of Ekalaka issues its own building permits within town limits². That town permit covers building only: septic permits stay with the Carter County Sanitarian and zoning does not exist in either place^3,4. Montana nevertheless has a statewide building-code framework for residential and commercial buildings where state jurisdiction applies⁵. A covered project must go through plan review, and the permit holder must notify the inspector when work is ready and provide access for required inspections⁹. Montana's contractor-licensing law exempts an owner working on the owner's property, subject to its resale limitation, but that exemption does not waive applicable trade permits or inspections¹⁰. We could not confirm a Carter County certificate-of-occupancy rule; ask the Board of Commissioners before assuming one applies¹¹.

Carter County has no listed county building or inspection department, and the only local building permits come from the Town of Ekalaka inside town limits². For land outside town, first determine whether the project needs Montana Building Codes Program review^1,2. For a covered state project, submit construction plans and a Building Permit/Plan Review Application to the state program⁹. The permit holder then calls for required state inspections as work becomes ready⁹. The Carter County Sanitarian approves individual septic systems and can be reached at 406-436-2077^3,12. The Carter County Clerk & Recorder records deeds and plats and keeps septic-permit application forms on hand; the office number is 406-775-8749¹³. Questions without a named county department, including county-road access or a certificate of occupancy, should go to the Board of Commissioners at 406-775-8795¹¹.

Neither Carter County nor the Town of Ekalaka has zoning regulations³. Unincorporated Carter County therefore has no county zoning districts, minimum dwelling size, minimum lot size, setbacks, lot-coverage limit or building-height limit³. County zoning also does not restrict manufactured homes or accessory dwellings in unincorporated Carter County³. These answers concern zoning only: subdivision, septic, floodplain and state construction rules can still control a project³. Carter County regulates the creation of new lots through subdivision rules, including a local-review exemption for agricultural-purpose divisions³. Federal obstruction protection also remains around Ekalaka Airport despite the absence of local zoning³.

Every individual septic system in Carter County requires a drainfield permit and approval by the Carter County Sanitarian⁴. Development covering less than 20 acres receives review from both the County Sanitarian and Montana DEQ³. Montana's subdivision sanitation review covers water supply, sewage disposal, solid waste and storm drainage, but a Certificate of Subdivision Approval does not replace the local drainfield permit⁴. Only about 32.7% of Carter County soils are rated without severe limitations for a conventional septic drain field, so settle septic feasibility before choosing a homesite or closing on land⁸. We could not confirm the county's septic inspection stages or an approved off-grid sanitation alternative; ask the Sanitarian what site evaluation, design and inspections apply to the parcel¹².

Carter County zoning does not restrict RV occupancy, temporary camping or tiny-home occupancy on private land in unincorporated areas³. The same no-zoning answer applies to manufactured homes and accessory dwellings³. That freedom is limited to the zoning question: septic, subdivision, floodplain, airport-airspace and state construction requirements may still apply³. A single-family tiny home does not require a building permit unless a local government requires one by ordinance or resolution¹. Before occupying any RV or small dwelling, arrange legal wastewater disposal with the County Sanitarian because every individual septic system needs a drainfield permit³. Rules for Montana public-use sites and state trust land concern public land, not occupancy on private Carter County property^14,15.

1. Determine whether the project needs a building permit; a single-family residence does not unless a local government requires one by ordinance or resolution¹.
2. If a state permit is required, submit plans and the Building Permit/Plan Review Application, then notify the inspector as each required inspection becomes ready⁹.
3. Ask the Carter County Sanitarian to approve the septic system and issue the drainfield permit; development smaller than 20 acres also receives Montana DEQ review^3,4.
4. Confirm whether a proposed land division needs county subdivision review before relying on an exemption or recording new lots³.
5. For an exempt well, file the $400 Notice of Intent; DNRC says it will authorize or deny a correct, complete filing within 10 business days, and an approved project has five years to be completed and put to use⁷.
6. Secure an approach permit or right-of-way agreement before constructing or modifying access to a state highway⁶.
7. Ask the Board of Commissioners who administers floodplain permits before developing in a mapped hazard area^11,16.
8. Record the deed, plat or survey with the Clerk & Recorder¹³.

Start with water and wastewater: Carter County averages 16.1 inches of precipitation a year, and only about 32.7% of its soils are rated without severe limitations for a conventional septic drain field⁸. A groundwater permit is required above 35 gallons per minute or 10 acre-feet per year; a smaller development may qualify for the permit exception⁷. Check legal access as well as road condition, because a new or modified approach to a state highway needs an approach permit or right-of-way agreement before construction begins⁶. About 86.3% of county land has a slope of 15% or less, while federal land covers about 28% of the county⁸. The nearest city of 100,000 or more is about 195 miles from the county center, so price contractor and material logistics before closing⁸. Property taxes average about 0.4%, with a median annual bill near $782⁸.