Buying Land in Silver Bow County, Montana

One consolidated government, one zoning code -- currently being rewritten

Silver Bow County is Montana's smallest county by land area (roughly 719 square miles) and, since a close 1976 vote and a May 1977 effective date, has been governed as a single consolidated entity: the City and County of Butte-Silver Bow, run by an elected Chief Executive and a 12-member Council of Commissioners under a Home Rule Charter. That consolidation matters for land buyers in a specific way: rather than a separate city zoning code for Butte proper and a different (or absent) county zoning regime for the rest of Silver Bow County, one Planning Department administers one zoning ordinance -- Title 17 of the Butte-Silver Bow Municipal Code -- across the whole consolidated jurisdiction, alongside subdivision and floodplain regulations under the same office.

That single-code structure is currently in flux. Butte-Silver Bow contracted with Orion Planning + Design (the same firm behind the 2020 Comprehensive Plan) for a full audit and rewrite of the zoning ordinance, and a first complete draft was introduced to the Planning Board in June 2025, followed by a series of public open houses that summer. If you're evaluating a parcel's zoning classification and allowed uses, confirm with the Planning Department (406-497-6250) not just what the current code says but whether the rewrite has reached your district yet -- an ordinance actively being redrafted is a different risk profile than a long-settled one.

The Berkeley Pit and the Butte Priority Soils Operable Unit: a real, active Superfund site

This is the fact that dominates land buying in Silver Bow County and deserves to be taken seriously rather than treated as historical color: Butte is the center of the Silver Bow Creek/Butte Area Superfund site, listed on EPA's National Priorities List and, across its several operable units, one of the largest Superfund complexes in the country. The Berkeley Pit -- a roughly 1,600-foot-deep former open-pit copper mine now filled with about 900 feet of acidic, metals-laden water -- is permanently monitored, with the Horseshoe Bend Water Treatment Plant capable of treating up to seven million gallons of contaminated water a day to keep the pit's water level below a critical threshold. It is not a passive historical hazard; it's an actively managed engineering system that will require treatment indefinitely.

Separately, the Butte Priority Soils Operable Unit (BPSOU) covers more than 6 square miles -- over 4,000 acres of the Butte Hill -- and is under an active cleanup governed by a consent decree the U.S. District Court for Montana approved in September 2020, which requires Atlantic Richfield Company (the historically responsible party) to undertake or finance over $150 million in remediation, including removal of contaminated tailings at the Northside and Diggings East areas, sediment and floodplain work along Silver Bow and Blacktail Creeks, and stormwater and groundwater treatment. As of 2025, EPA was also proposing to lower the BPSOU-specific residential soil/dust cleanup threshold for lead. Because institutional controls and deed restrictions attach to specific parcels within these operable units -- limiting things like new residential construction, digging, or well use in some areas -- a buyer looking anywhere in or near the Butte Hill should ask EPA's Butte program office or Butte-Silver Bow directly whether a specific parcel falls inside an operable unit boundary and what controls, if any, run with its deed, rather than assuming a listing's silence means the answer is no.

On the more directly useful side: Butte-Silver Bow's Residential Metals Abatement Program (RMAP) offers free residential soil sampling for lead and arsenic, and where results warrant it, removal and replacement of contaminated soil -- funded through a financial agreement with Atlantic Richfield rather than billed to the homeowner. If you're buying an older home anywhere in the Butte area, calling RMAP (406-497-5040) to check a property's sampling history, or to request new sampling, is a concrete and free due-diligence step most buyers elsewhere in Montana simply don't have available to them.

Property tax: a local Assessor, but state valuation still applies

Butte-Silver Bow is one of the few Montana counties to maintain a locally titled Assessor's office (406-497-6290) -- but per the statewide framework described on the Montana hub, that office's role here is narrower than the title suggests. It handles personal and business property tax administration and reports to the state, while actual real-property valuation and classification for tax purposes remains a function of the Montana Department of Revenue's Property Assessment Division, whose Butte field office is separately located at 130 N Main St. Don't assume the county Assessor's office is the right first call for a real-property valuation dispute or reassessment question -- start with the state DOR field office instead, and use the county Treasurer's office for actual tax bill payment and collection.