Blaine County (county seat: Chinook) covers 4,239 square miles with a population of 7,044 (2020). Official county website: www.blainecounty-mt.gov/. This page summarizes the verified building-regulation posture of unincorporated Blaine County land; the full 10-dimension scorecard with every source receipt lives on its Freedom Map card.
On non-tribal unincorporated county land there is no county building department and Blaine County does not appear on the DLI certified-jurisdiction list, so a single-family residence is exempt from the state building permit; farm/ranch buildings and private storage/garages are explicitly exempt, and owner-occupant electrical/plumbing exemptions apply. Permit-free residential building. Scored 9. NOTE: inside the Fort Belknap Reservation, building/land-use is governed by federal/tribal (BIA/tribal) authority, not the county — that trust land is outside this score.
The claim above is source-verified (official statute/county documents; URL, direct quote, and date on the full card). Method: how we verify.
No county's freedom erases state law: septic/wastewater permitting (health authority), well permits and water rights (state engineer/DNR), floodplain rules with federally connected financing, and — in some states — state-run electrical inspections. The full card details which of these bite in Blaine County and how hard.
The score describes unincorporated county land only. Inside Blaine County, incorporated municipalities set their own, usually stricter, rules — including: Chinook (city, county seat), Harlem (city), Turner / Zurich area. Land inside town limits follows town code.
Building rules are the first question people ask about Blaine County — and the easiest one to answer. They're rarely the one that decides it. The full card grades all ten dimensions, every claim quoted from the county's own code.
What the Blaine County card answers that this page doesn't:
It's a real map. Click any county in the country and see how it grades — that part costs nothing, and you can compare Blaine County against its neighbors before you spend a dollar.
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Last verified July 2026 · Not legal advice — confirm current rules with the county, the state, and a professional before buying or building.