Off-Grid Living in Beaverhead County, Montana

Beaverhead County is Montana's biggest county by land area but one of its emptiest by population, and that shapes how it handles off-grid living. There are only two incorporated towns here, Dillon (the county seat) and Lima. If your land sits inside either town's limits, that town's own building department runs permitting, not the county. Everywhere else, unincorporated Beaverhead County, the Land Use and Planning Department is your main point of contact for land-use questions, and the county's Environmental Health (Sanitarians) office handles septic.

Zoning: I could not find an official county page describing a countywide zoning ordinance with parcel-by-parcel districts. The Land Use and Planning Department's own description of its work centers on the Growth Policy, subdivision regulations, the Big Hole River Conservation Development Standards, and a Wireless Communications Facilities Ordinance, not a general zoning code. That lines up with Beaverhead's reputation as a historically unzoned county, but I'm treating "no zoning" as unconfirmed rather than official fact. Call the county to check your specific parcel.

Dwellings, tiny homes, RVs: Montana has adopted IRC Appendix Q at the state level for tiny homes on foundations, and tiny homes on wheels generally get treated like RVs. I found no Beaverhead-specific ordinance addressing tiny homes or RV occupancy, so the state baseline is what applies until you confirm otherwise with the county.

Building permits: The county issues building permits only for unincorporated land; Dillon and Lima handle their own inside city limits. Montana law has a single-family exemption from state building code review, but whether Beaverhead County has locally opted into stricter permitting isn't confirmed from what I found. The Montana Building Codes Bureau is the backstop state authority.

Septic: This is the one area where Beaverhead County is very clearly hands-on. The county's Environmental Health office issues septic permits under the county's own Wastewater Regulations, which implement state DEQ subsurface wastewater standards. You apply on county forms, and the county sanitarian inspects the system before it gets backfilled. This applies to any occupied structure generating wastewater, on-grid or off.

Greywater and rainwater: Neither has a distinct county policy that I could find. Both default to Montana's general baseline: greywater is more tightly restricted than septic disposal, and basic rooftop rainwater collection for non-potable use is generally fine.

Wells and water rights: Well permitting and exempt-well rules run through the state DNRC, not the county. The county's subdivision regulations reference DEQ wastewater standards and well-isolation zones as part of septic site review for new development, but actual water rights and well drilling permits are a state matter.

Off-grid utility disconnection: No county ordinance was found requiring grid electric connection for a single-family home. But if you're generating wastewater, you need a septic permit regardless of whether you're on the grid, and any land division can trigger the county's subdivision review.

Given how much of Beaverhead's rulebook is inherited from the state rather than written locally, calling the county offices directly before you buy or build is worth the time.