Mont. Code § 82-4-123
A fee of $50 shall be paid before the mine-site location permit required in this part may be issued. The operator shall also file with the department a bond payable to the state of Montana with surety satisfactory to the department in the penal sum to be determined by the department of not less than $200 or more than $10,000 for each acre or fraction thereof of the area of land to be disturbed by preparatory work, with a minimum bond of $5,000, conditioned upon the faithful performance of the requirements set forth in this part and of the rules of the department. In determining the amount of the bond within the above limits, the department shall take into consideration the character and nature of the surface and subsurface disturbances, the future suitable use of the land involved, and the cost of removing or burying facilities, subsidence stabilization, water controls, backfilling, grading, topsoiling, and reclamation to be required. Notwithstanding the above limits, the bond may not be less than the total estimated cost to the state of completing the work described in the reclamation plan.
§ 82-4-123, MCA