Montana approved the Montana Environmental Policy Act in the year 1971. MEPA recognizes that "each person is entitled to a healthful environment." To be entitled to a healthful environment implies that each person in the State of Montana has a claim to a healthful environment.

• MEPA requires state agencies to prepare a regulatory restriction analysis whenever the agency prepares and EA (Environmental Assessment) or an EIS (Environmental Impact Statement) for a proposed action on private property that appears to restrict the use of the private property.
• MEPA narrows the scope of alternatives that may be analyzed in an environmental review and includes the comments of the project sponsor in the determination of reasonableness and feasibility. It also requires a review of the beneficial aspects and economic advantages of a proposed project and a discussion of the beneficial and adverse environmental, social, and economic impacts of a project's non-completion.
• MEPA states that it may not be used to withhold, deny, or impose conditions on a permit or other authority to act without concurrence of the project sponsor.
• MEPA proposes specific timeframes for the completion of environmental reviews. MEPA also provides some statutory definitions.
• MEPA created the Environmental Quality Council (EQC), which is a legislative agency.
• When a proposed action may significantly affect the quality of the human environment, MEPA and NEPA both requires the State or Federal Agencies to prepare an EIS.
• Under the MEPA Model Rules, the public controversy that a proposed action will generate is not considered in determining significance.