Well Water in Glacier County, Montana

The 2016 Blackfeet Water Compact gave the Tribe nearly all groundwater on the reservation

The Blackfeet Water Rights Compact -- negotiated among the Blackfeet Tribe, the State of Montana, and the United States, and signed into federal law on December 16, 2016 -- quantified the Tribe's reserved water right at roughly 750,000 to 800,000 acre-feet of water annually, and gives the Tribe the right to essentially all groundwater within the reservation, including water in the reservation's lakes, ponds, and wetlands, not just its rivers and streams. The compact also created a process specifically aimed at protecting groundwater from new developments in areas where supply may be inadequate in either quantity or quality.

Several basins are now closed to new DNRC-processed well and water-right applications

Under the compact, in the portions of Basins 40F, 40T, 41L, and 41M that fall within the reservation, and along the mainstems of reservation-boundary streams, the Montana Department of Natural Resources and Conservation is barred from processing or granting any new appropriation application received after the compact's ratification. That's a direct, practical change from how DNRC permitting works everywhere else covered on the state hub: in these specific basins inside the reservation, the state's ordinary process for a new well or water right effectively stopped taking new applications once the compact took effect.

The compact does leave one specific path open for fee-land owners in these closed basins: DNRC may still issue a certificate of water right or permit for use on fee land as an "Excepted Right" under the compact's Article IV.G.1, drawing from sources that would otherwise be closed. This is a narrower, compact-defined process rather than DNRC's standard statewide permitting or exempt-well framework, and it applies specifically to fee land within these basins -- not to trust land, which falls under tribal water-right administration instead.

What this means before you plan a well on reservation-boundary land

If you're evaluating a Glacier County parcel inside the Blackfeet Reservation boundary and plan to rely on a new domestic well, don't assume the standard Montana exempt-well or DNRC permit process described in the state's general water-rights material applies unmodified. First confirm whether the parcel falls within Basin 40F, 40T, 41L, or 41M, or along a reservation-boundary stream mainstem -- DNRC's Compact Implementation staff can confirm current basin boundaries for a specific parcel. If it does fall within a closed area and the land is fee land, ask DNRC specifically about the Excepted Rights process under Article IV.G.1 rather than a standard new-appropriation application. Because the Tribe administers tribal water rights on the reservation while the state administers state water rights, it's also worth contacting the Blackfeet Nation's own water-compact office in Browning to understand how a specific well plan interacts with tribal water-right administration before you finalize a purchase that depends on a new well.