Off-Grid Living in Carter County, Montana

I'll be upfront: Carter County, Montana is one of the harder places to research because it's so sparsely populated that a lot of the usual county paperwork trail (zoning department pages, septic permit forms, building code adoption notices) just isn't published online in a way I could confirm. So this guide leans heavily on stating what the state of Montana does by default, and flagging where Carter County itself is a question mark you'll need to close by calling the courthouse in Ekalaka.

Zoning. I could not confirm that Carter County has adopted a countywide zoning ordinance. The county's own Resource Use Plan talks about growth policy and coordinating land use (relevant since roughly a third of the county is federal or state land), but growth policies aren't the same thing as zoning. Montana's Land Use Planning Act makes zoning mandatory mainly for larger counties and gives smaller ones like Carter the option to opt in, not a requirement. So my working assumption, not a guarantee, is there's no countywide zoning restricting where you build on raw land, but incorporated towns like Ekalaka could have their own separate rules.

Dwellings and building permits. Here's a genuinely useful state-level fact: Montana's Business Standards Division says the state doesn't require building permits for single-family residences unless the local jurisdiction has specifically elected to become a certified enforcement authority. I found no evidence Carter County has done that. So a single-family off-grid home may well be exempt from a building permit by default state rule, but I can't confirm the county's election status either way, so please verify directly before you build.

Septic and composting toilets. Statewide, Montana DEQ sets the technical standards for onsite wastewater systems and local health departments handle the actual permitting and site evaluations. I could not find Carter County's own environmental health page (a similarly-named site, carterhealth.org, is actually Carter County, Kentucky, so ignore that one). Call the county health office to find out who administers septic permits locally.

Greywater and rainwater. No Carter County ordinance turned up on either topic, so state rules likely apply: basic rooftop rainwater collection for personal, non-potable use appears to be fine, while greywater reuse is more restricted under state administrative rules, particularly for subsurface irrigation.

Wells and water rights. The county's Resource Use Plan explicitly says water allocation follows Montana's Prior Appropriation Doctrine under the 1973 Water Use Act. Small "exempt" wells generally don't need a pre-drilling permit from DNRC below a certain use threshold, but you do need to file a notice of completion.

Utility disconnection. I found nothing requiring grid connection for a single-family home in Carter County. That said, local subdivision or septic site-evaluation requirements could indirectly shape where and how you can live off-grid, so this is worth a direct call.

Bottom line: Carter County looks permissive on paper mostly because so little has been formally adopted, not because someone has affirmatively blessed off-grid living. Confirm everything with the county before you commit money to land.