For decades, drilling a domestic well on Montana land was one of the few things you could do without asking the state first. If your well pumped 35 gallons a minute or less and used no more than 10 acre-feet a year, it was exempt — you drilled it, your driller filed a log, and that was largely that.
That changed this year. Under House Bill 681, passed by the 2025 Legislature and effective January 1, 2026, you now have to notify the Department of Natural Resources and Conservation before you put the water to use — and DNRC has to say yes.
File a Notice of Intent to Appropriate Groundwater (Form 602I) with DNRC, pay $400, and wait for authorization. DNRC has 10 business days to authorize or deny once your notice is complete. Then, within 60 days of actually putting the water to use, file the Notice of Completion (Form 602).
This trips people up, and a lot of summaries get it wrong. The statute requires the notice before appropriating the groundwater — that is, before putting it to beneficial use. DNRC states plainly that the Notice of Intent can be submitted before or after the well is drilled.
That said, filing first is the sensible order of operations. A denial after you've paid to drill is an expensive way to learn your parcel didn't qualify.
The old Notice of Completion was paperwork. This is not. The statute says DNRC "shall review the notice for compliance… and shall authorize or deny the notice of intent." If your proposed use doesn't qualify, it gets denied and you're routed to the full water right permit process — a different, much longer road.
DNRC also can no longer process a Notice of Completion without an authorized Notice of Intent behind it, unless your Form 602 was already pending before January 1, 2026.
On February 14, 2024, Montana's First Judicial District Court decided Upper Missouri Waterkeeper v. DNRC (Cause No. BDV-2022-38), widely known as the Horse Creek Hills case. A developer had been treating each phase of a four-phase subdivision as separately entitled to its own 10 acre-feet under the exemption.
The court said no: all phases of a multi-phase development are one combined appropriation. Every lot in the subdivision now shares a single 10 acre-foot ceiling. If you're buying a lot in a phased subdivision, ask about this directly — the water math may already be spoken for.
Land inside the Yellowstone Controlled Groundwater Area — roughly 1,200 square miles adjacent to the park, created by the 1994 National Park Service–Montana water compact — sits outside the exempt well system entirely. Every groundwater appropriation there requires a permit, whatever the size.
DNRC lists Gardiner, Jardine, Corwin Springs, Cooke City–Silver Gate, West Yellowstone, Hebgen Lake, and Gallatin Canyon south of Big Sky as inside the YCGA. Livingston and the northern Paradise Valley are almost certainly outside it, but the legal boundary is a map, not a line you can eyeball. If your parcel is anywhere south of Yankee Jim Canyon, call the DNRC Bozeman Regional Office at (406) 586-3136 and have them check before you spend a dollar.
It's a permit, but a streamlined one. A Type A application covers 35 gpm or less and up to 10 acre-feet, uses an abbreviated process, gives the Park Service 60 days to review, and requires a water meter — which DNRC supplies free. You aren't required to prove the full statutory permit criteria the way a large appropriator would be.
1. Confirm whether your parcel is inside the Yellowstone CGWA — call DNRC Bozeman, (406) 586-3136. 2. If outside, file Form 602I with the $400 fee and wait for authorization. 3. Drill. 4. Within 60 days of first use, file Form 602. 5. Keep the authorization with your deed records — the next buyer's title work will want it.
Primary sources: MCA 85-2-306 (2025); HB 681, Ch. 708, Laws of 2025; DNRC Exceptions to Permit Requirements; DNRC Exempt Well Updates; DNRC Basin Closures, Stream Depletion & Controlled Ground Water Areas; ARM 36.12.1201–1205; Upper Missouri Waterkeeper v. DNRC, BDV-2022-38 (Mont. 1st Jud. Dist. Feb. 14, 2024). General information about Montana law, not legal advice. Confirm with DNRC before filing.
Tell us about your project and we'll point you toward people who do it in your county — or tell you honestly if we don't know anyone good there yet. Start here.