Mont. Code § 15-24-3101
It is the policy of the state of Montana that the tax classifications, rates, abatements, and exemptions in 15-6-158, 15-6-159, and this part and amendments made by Chapter 2, Special Laws of May 2007, in 15-6-141 and 15-6-157 are to be strictly limited to new investments that qualify under the standards established in 15-6-158, 15-6-159, and this part and amendments made by Chapter 2, Special Laws of May 2007, in 15-6-141 and 15-6-157. The provisions of 15-6-158, 15-6-159, and this part and amendments made by Chapter 2, Special Laws of May 2007, in 15-6-141 and 15-6-157 do not apply to any previously existing properties or to any new investments or property that does not qualify under 15-6-158, 15-6-159, and this part and amendments made by Chapter 2, Special Laws of May 2007, in 15-6-141 and 15-6-157. It is also the policy of the state of Montana that the classifications, rates, abatements, and exemptions in 15-6-158, 15-6-159, and this part and amendments made by Chapter 2, Special Laws of May 2007, in 15-6-141 and 15-6-157 are to encourage investment in energy development that is consistent with maintaining a clean and healthful environment and that may not otherwise occur without 15-6-158, 15-6-159, and this part and amendments made by Chapter 2, Special Laws of May 2007, in 15-6-141 and 15-6-157. Sections 15-6-158 and 15-6-159 and this part and amendments made by Chapter 2, Special Laws of May 2007, in 15-6-141 and 15-6-157 are not to be interpreted as a precedent for reducing the taxation of any other property in the state or for affecting the use of any property valuation method for tax purposes established under law to meet the standards of the Montana constitution and law. The department of environmental quality and the department of revenue are directed to administer and interpret 15-6-158, 15-6-159, and this part and amendments made by Chapter 2, Special Laws of May 2007, in 15-6-141 and 15-6-157 strictly in accordance with this policy. Any ambiguities in 15-6-158, 15-6-159, and this part and amendments made by Chapter 2, Special Laws of May 2007, in 15-6-141 and 15-6-157 are to be resolved in favor of the strict reading of this policy.
§ 15-24-3101, MCA