Mont. Code § 82-4-225
The department may increase or reduce the area of land affected by an operation under a permit on application by an operator, but an increase may not extend the period for which an original permit was issued. An operator may, at any time, apply to the department for an amendment of the permit so as to increase or reduce the acreage affected by it. The operator shall file an application and map in the same form and with the same content as required for an original application under this part and shall file with the department a supplemental bond in the amount to be determined under 82-4-223 for each acre or fraction of an acre of the increase approved. All procedures of this part pertaining to original applications apply to applications for the increase of the area of land affected, except for incidental boundary revisions. If the department approves a reduction in the acreage covered by the original or supplemental permit, it shall release the bond for each acre reduced, but the bond may not be reduced below $10,000, except as provided in 82-4-223.
§ 82-4-225, MCA
Contingent Termination: Section 6 of Laws 2023, Ch. 524 provides: "[This act] terminates on the date that the department of environmental quality certifies to the code commissioner that the office of surface mining of the United States department of the interior disapproves the changes to Montana's program that are provided in [this act]. The department of environmental quality shall submit certification within 60 days of the occurrence of the contingency."