County seat: Kalispell
Building in Flathead County
How zoning works here
This county administers zoning across the unincorporated county.
Flathead County has countywide zoning regulations adopted in 1993 (last revised April 2022) covering unincorporated areas, with numerous zoning districts ranging from agricultural to commercial and industrial; incorporated cities maintain their own zoning.
This county publishes a zoning GIS layer. View the county service.
Building permits
This county has no county building department
Flathead County has NO county building department. Building permits in unincorporated Flathead County are issued by the Montana State Building Codes Bureau (DLI). Within Kalispell, Whitefish, and Columbia Falls city limits, the respective city building departments issue permits. Note: Flathead County's Planning & Zoning Office requires a site plan submission before development in certain commercial and industrial zoning districts.
What that means for you. Fewer permits and lower cost — and nobody but you checking the work. Budget for independent inspections and choose contractors on verifiable completed work.
Who to call
Building permits
Montana Department of Labor & Industry Building Codes Program (state authority for unincorporated Flathead County)
Sanitation / septic
Flathead County Environmental Health (Flathead County Health Department)
Floodplain administrator
Flathead County Planning & Zoning Office (Floodplain Administration)
State building codes
Montana Department of Labor and Industry, Building Codes Bureau
Cities with their own jurisdiction
Inside these limits the municipality, not the county, is generally the planning and permitting authority: Kalispell, Whitefish, Columbia Falls, Bigfork, Lakeside, Polson, Ronan.
Check a specific parcel in Flathead County
County rules are only part of the picture. Terrain, soils, septic feasibility, flood, wetlands and access are parcel-specific.
County authority details researched from primary county sources and verified 2026-08-14. County rules change and this page is a starting point, not a determination. Confirm anything you intend to rely on directly with the office that administers it. Sources: flathead.mt.gov, maps.flatheadcounty.gov, flatheadcounty.gov, flatheadcounty.gov