Off-Grid Living in Sanders County, Montana

I'll be upfront: Sanders County, Montana is one of those places where the paperwork trail is thinner than you'd like, and a lot of what I found points to "not confirmed" rather than a clean yes or no. Here's what I could actually verify from official sources, and where the gaps are.

Zoning. Sanders County doesn't appear to have a comprehensive countywide zoning code, based on what's published by the county's Land Services Department. That department handles subdivision regulations, floodplain rules, road encroachment permits, and a few other specific areas, but I found no countywide zoning resolution. Montana state law (the Real Property Owners Zoning Enabling Act) lets county commissioners create zoning districts, or lets landowners petition for one, but I saw no evidence Sanders County has done this on a countywide basis. So raw-land occupancy is largely unregulated outside incorporated towns, though that could change if a local zoning district gets petitioned into existence in a specific area.

Dwellings, tiny homes, RVs. No county-specific ordinance turned up. Montana law does let counties set up zoning districts that specifically allow tiny dwelling units, but that's discretionary and I found nothing showing Sanders County has adopted one. Absent local rules, I'd assume the state baseline applies: RVs and tiny homes on wheels treated as RVs, foundation-built tiny homes potentially following IRC Appendix Q if the state building code program is in play.

Building codes. This is a real gap. Montana allows counties to opt into certifying their own local building code program through the state's Building Codes Program (part of the Department of Labor and Industry); otherwise the state program covers it by default. I found no page announcing that Sanders County runs its own certified program, so my best read is that the state program is the fallback, but confirm this directly with the county or the state Building Codes Program before you build.

Septic and composting toilets. This one is solid and confirmed: the Sanders County Environmental Health Office requires a permit for any new, repaired, or replaced septic system, administered by the county's registered sanitarian. The county's wastewater regulations must meet or exceed Montana DEQ's statewide standards. If you're going composting-toilet-only, you'll still likely need to deal with greywater disposal through the same permitting office, so don't assume composting toilets sidestep the process entirely.

Greywater and rainwater. No county-specific rules found for either. I'd lean on the state's general administrative baseline, which allows in-home greywater reuse without a permit in many cases (subsurface irrigation is more restricted), and no statewide bar on basic rooftop rainwater collection for non-potable use. Still, always double check with Environmental Health since county practice can differ from state text.

Wells. Sanders County Environmental Health issues well permits (new, replacement, or relocation) layered on top of Montana's DNRC exempt-well framework. There's also a DEQ Certificate of Site Approval process that can come into play for well and septic siting.

Utility disconnection. No ordinance found that requires grid electrical hookup for occupancy. But you can't avoid the county's well and septic permitting for water and wastewater, so full off-grid independence has that one hard requirement layered in by the county's Environmental Health office.

Given how much of this county's regulatory footprint is concentrated in septic/well permitting rather than zoning or building codes, my honest take is: septic and well rules are the firm, confirmed constraints here, and everything else is comparatively open until proven otherwise by a call to the county.