County seat: Billings
Building in Yellowstone County
How zoning works here
This county does not administer general zoning outside incorporated cities and towns. That is common in Montana and frequently misunderstood: no zoning does not mean no rules. Subdivision review, sanitation review, floodplain regulation, covenants and state building code can all still apply.
Yellowstone County has limited zoning — primarily around Laurel (Laurel-Yellowstone County Planning Board jurisdiction, approximately 1 mile beyond Laurel city limits); most of the unincorporated county outside that area has no county zoning.
Building permits
This county has no county building department
Yellowstone County explicitly does NOT issue building permits or Certificates of Occupancy for structures outside the city limits of Billings. Per the county's own FAQ: 'Yellowstone County does not issue Building Permits or Certificates of Occupancy for structures outside the city limits of Billings.' Non-exempt structures in unincorporated areas fall under the Montana State Building Codes Bureau (DLI). Within Billings city limits, the City of Billings Building Division issues permits.
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
Planning
Yellowstone County / City of Billings Joint City-County Planning Division
Building permits
Montana Department of Labor & Industry Building Codes Program (state authority for unincorporated Yellowstone County)
Sanitation / septic
RiverStone Health Environmental Health Services (Yellowstone City-County Health Department)
Floodplain administrator
Yellowstone County Public Works — Floodplain Administration (Monica Plecker, Administrator)
Subdivision review
Yellowstone County / City of Billings Joint City-County Planning Division
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: Billings, Laurel, Broadview.
Check a specific parcel in Yellowstone 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: www.billingsmt.gov, www.yellowstonecountymt.gov, www.yellowstonecountymt.gov, www.yellowstonecountymt.gov