Off-Grid Living in Fallon County, Montana

Fallon County sits out in far southeastern Montana, and if you're eyeing raw land here for an off-grid setup, the good news is that the county has not adopted a countywide zoning ordinance. Based on official county planning board minutes, Fallon County has only just started surveying residents about whether to adopt zoning at all, so as of now, unincorporated land is largely unregulated on the land-use front. The exception is floodplain development, which the county Planning Department actively permits regardless of where you are in the county. Zoning activity that does exist, like work happening for the City of Baker and a conditional use permit process in the Town of Plevna, applies inside those municipal boundaries, not out in the county.

Dwellings are murkier. I didn't find a Fallon County-specific rule on tiny homes or RVs used as full-time residences, so in the absence of zoning, occupancy itself isn't clearly restricted outside city limits, but you'd still need a septic or wastewater permit for any occupied structure, which brings you back into contact with the county regardless of what you're living in.

On building codes, Montana's state building codes program lets cities and counties opt in to enforcing residential codes, but single-family homes are exempt from state permitting unless a local government has opted in. I couldn't confirm from official sources whether Fallon County has opted in for unincorporated areas, so this is a "call and ask" item.

Septic is where the county is clearly active. The Sanitation/Environmental Health office issues wastewater permits and reviews composting toilets under the same process, working within the state DEQ/DPHHS framework. Greywater isn't separately addressed by the county, so it falls back on the state ARM rules, generally allowing indoor non-potable reuse without a permit while restricting subsurface irrigation, still reviewed by the county sanitarian when you apply for your septic permit.

Rainwater harvesting has no county restriction that I could find, consistent with Montana's general lack of a statutory ban on rooftop collection for personal use.

Wells run through the state DNRC exempt-well process rather than any county permitting system. DNRC recommends calling their regional office before putting new groundwater to use, especially since lots created after October 17, 2014 may face combined appropriation limits.

Living fully off-grid, meaning no utility hookup at all, isn't addressed one way or the other by any Fallon County ordinance I found. Practically, it comes down to whether your well and septic pass muster with Sanitation/Environmental Health, since there's no zoning code yet to trigger a broader review.