Data-center law in Montana

Mont. Code Ann. Title 76, chapter 2

Applies to both

Authorizes a board of county commissioners to create a planning and zoning district and appoint a planning and zoning commission, but only on petition of 60% of the affected real property owners in a proposed district of at least 40 acres; a separate part of this chapter governs zoning by an incorporated city. A county that has received no such petition has adopted no zoning ordinance, so a data center sited in one proceeds under this chapter with no county zoning review or entitlement process.

Source: Full text of law

Mont. Code Ann. Title 75, chapter 20

Applies to both

Requires a certificate of compliance from the Department of Environmental Quality before a person commences construction of a covered facility, defined to include an electric transmission line and associated facilities of a design capacity over 69 kilovolts (with exceptions for shorter, lower-voltage lines), and an electrical generation facility, other than a qualifying small power production facility, normally operated to produce 20 average megawatts or more of electric power.

Large onsite or co-located generation built to power a data center can cross this threshold; the Act excludes an energy storage facility or a green hydrogen facility, pipeline, or storage system from its certificate requirement, and does not reach a data center's own computing or building infrastructure.

Source: Full text of law

Mont. Code Ann. Title 69, chapter 3

Applies to both

Defines a public utility to include a corporation, company, individual, or association that owns, operates, or controls plant or equipment for producing, delivering, or furnishing heat, light, power in any form, water for business or household use, or regulated telecommunications service, subject to exceptions for privately owned systems that do not serve the public and certain municipal and county water or sewer systems.

This chapter places retail electric, gas, and water service to a data center under Public Service Commission rate and service regulation, and the commission's certificate and tariff provisions govern the utility side of a large-load interconnection.

Source: Full text of law

Mont. Code Ann. 75-2-211

Applies to both

Requires the owner or operator of machinery, equipment, or a facility the Department of Environmental Quality finds may directly or indirectly cause or contribute to air pollution to file a permit application before construction, installation, or alteration, generally no later than 180 days beforehand. A data center's backup generator fleet permits under this section and the department's implementing rules for new and modified sources.

Source: Full text of law

Mont. Code Ann. 15-6-162

Applies to private

Classifies the land, improvements, furniture, fixtures, equipment, tools, and supplies of a qualifying data center as class seventeen property, taxed at 0.9% of market value, well below the standard business equipment rate.

A facility qualifies at 300,000 square feet with at least $150 million invested in land, improvements, personal property, and software since construction commencing after June 30, 2017, or at 25,000 square feet of new or expanded area with at least $50 million invested over a 48-month period since construction commencing after January 1, 2019; property under construction can qualify provisionally on the taxpayer's certification that it will meet these thresholds within 2 years.

A 2025 amendment (Ch. 678, L. 2025) extended the same classification and 0.9% rate, for 10 years from the start of construction, to onsite electrical generation and storage systems used at least 80% for the facility's own consumption on an annualized basis, with the 80% requirement suspended during a governor-declared electrical generation emergency for a facility that makes its onsite backup generation available to the utility.

Source: Full text of law