Babb

Glacier County (Cut Bank county seat; northwest Montana on the Canadian border; ~13,800 residents across 3,026 sq mi; the dominant land-use feature is the Blackfeet Indian Reservation, which covers approximately 65% of the county's area; Glacier National Park's east entrance corridor (St. Mary, Babb, East Glacier Park) sits on the western edge; the Rocky Mountain Front rises out of the Plains in the western county) does not maintain a comprehensive countywide zoning code applicable to fee-simple parcels. Land use in Glacier County is partitioned across THREE jurisdictional regimes: (1) the Blackfeet Indian Reservation (Blackfeet Tribe Land Use Code under Blackfeet Tribal Business Council authority and BIA trust-land oversight; covers Browning, Heart Butte, Babb, St. Mary, and most reservation parcels - approximately 65% of county area); (2) incorporated Cut Bank (~3,000 residents, the only incorporated city in Glacier County, located outside the reservation); and (3) unincorporated non-reservation Glacier County (a strip on the eastern county margin and small inholdings, generally unzoned). Montana SB 528 (2023, Mont. Code Ann. § 76-2-345) preempts MUNICIPAL ADU restrictions and applies to ALL incorporated Montana cities; Cut Bank is squarely subject. SB 528 does NOT reach unincorporated county land OR tribal trust land - the Blackfeet Reservation is governed by Blackfeet Tribe land-use authority under the Indian Reorganization Act (25 U.S.C. § 5101 et seq.) and applicable BIA regulations, NOT by Montana state preemption. ADU permissibility on reservation land is determined by Blackfeet Tribe Land Use Code and BIA realty oversight, not by SB 528.

State-floor overlay: Montana SB 528 establishes a state ADU floor for incorporated Montana cities; Cut Bank (only incorporated city in Glacier County) is squarely subject. SB 528 does NOT reach the Blackfeet Indian Reservation (tribal jurisdiction) and does NOT reach unincorporated non-reservation Glacier County. Reservation ADU permissibility is determined by Blackfeet Tribe Land Use Code and BIA realty oversight.

Glacier County's overlay landscape is dominated by federal and tribal land management. Six categories are material: (1) Blackfeet Indian Reservation tribal jurisdiction - covers approximately 65% of county area; tribal land-use authority preempts state and county zoning; trust land is also tax-exempt. (2) Glacier National Park boundary - the park's east entrance (St. Mary, Many Glacier, Two Medicine, Cut Bank Creek) abuts the western edge of the county; NPS has no direct authority over private land but federal-action triggers can apply. (3) Wildland-Urban Interface - Glacier NP, the Bob Marshall Wilderness Complex (Sawtooth Range, Rocky Mountain Front), and tribal forest land all generate WUI exposure; the 2017 Sprague Fire and other recent burns have driven elevated insurance underwriting caution. (4) FEMA NFIP floodplain along the St. Mary River, Two Medicine River, Cut Bank Creek, Milk River. (5) Grizzly bear recovery zone - the Northern Continental Divide Ecosystem (NCDE) covers most of western Glacier County; ESA Section 7 consultation can apply to federally-financed construction. (6) NRHP historic resources - the Going-to-the-Sun Road National Historic Landmark (within Glacier NP), Cut Bank historic structures, and Blackfeet cultural resource sites administered through Blackfeet THPO and Montana SHPO.

• Blackfeet Indian Reservation - tribal land-use jurisdiction — The tribal/non-tribal jurisdictional split is the most important single factor for ADU work in Glacier County. Builders must determine parcel jurisdiction before any other planning. Trust-land home-site leasing through Blackfeet Tribe is a different model than fee-simple ownership and produces a very different ADU economics profile (no resale fee-simple, generation-to-generation lease assignments).
• Wildland-Urban Interface - Glacier NP, Bob Marshall Wilderness Complex, Rocky Mountain Front — ADU economics in St. Mary, Many Glacier, and East Glacier Park face elevated insurance cost (15-30% premium) and tightening underwriter availability. Tourism-driven STR demand offsets some of the cost where it is permitted. Cut Bank (eastern county, on the Plains) is essentially outside the WUI overlay.
• FEMA NFIP Special Flood Hazard Areas - St. Mary River, Two Medicine River, Cut Bank Creek, Milk River — Spring snowmelt drives late-spring flooding peaks; Glacier NP is the source of the St. Mary and Two Medicine drainages. ADUs in mapped SFHA must be elevated to or above Base Flood Elevation; this can add $20,000-$40,000 to construction cost.
• Glacier National Park boundary / east entrance corridor — STR demand in St. Mary, Many Glacier, and East Glacier Park is among the most concentrated in Montana, driven by Glacier NP tourism. Reservation jurisdiction in St. Mary and East Glacier Park complicates fee-simple ADU economics; many lodging operations are tribal lease-held.
• Northern Continental Divide Ecosystem (NCDE) Grizzly Bear Recovery Zone — Cash and conventional-financed ADUs face minimal direct ESA friction but bear-resistant storage compliance is widespread practice. Federally-financed projects can face 60-180 day Section 7 consultation timelines.
• Going-to-the-Sun Road NHL; Cut Bank historic structures; Blackfeet cultural resources — ADU work on Blackfeet reservation land triggers Blackfeet THPO consultation. ADU work on NRHP-listed contributing properties triggers Section 106 review only if federal financing or permitting (FHA, USDA RD, HUD-184) is involved.

Glacier County permitting is split across three regimes. (1) Blackfeet Indian Reservation: Construction on tribal trust land or allotted trust parcels requires a Blackfeet Tribe land-use permit (administered by the Blackfeet Tribal Business Council Land Department) plus BIA realty review under 25 CFR Part 162 (residential leasing) and 25 CFR Part 169 (access rights-of-way) where applicable. Tribal home-site leases and assignments are the typical mechanism for residential development on trust land - fee-simple ownership is generally not available on trust parcels. ADU construction on reservation fee-simple parcels (small inholdings) follows non-tribal county process but tribal jurisdiction may still attach for some purposes. (2) Cut Bank (incorporated): city building department issues permits per state-adopted IRC 2018 with Montana amendments. SB 528 preemption applies. (3) Unincorporated non-reservation Glacier County: no county building department, no county zoning. ADU construction proceeds with state-level oversight only (Montana DEQ for septic, DNRC for wells, county floodplain administrator for SFHA permits). Note: SB 528 has NO application here since this strip contains no incorporated cities. Glacier County is in IECC climate zone 6B-7; St. Mary and the Rocky Mountain Front face elevated snow loads (60-90 psf typical, higher at the Glacier NP boundary).