The City of Missoula operates its own independent building and planning department for properties within city limits, while Missoula County Development Services handles unincorporated areas. Projects in unincorporated areas are subject to additional review for floodplains, wildland-urban interface fire zones, and specific zoning district requirements.
How this fits with the state
The state authority here is Montana Department of Labor and Industry. The county file does not replace that — it adds the permit office, local overlays, and the actual filing path.