Mont. Code Ann. § 61-3-726

The initial application for proportional registration of a fleet shall state the mileage data with respect to the fleet for the preceding year in this and other jurisdictions. If operations were not conducted with this fleet during the preceding year, the application shall contain a full statement of the proposed method of operation and estimates of annual mileage in this state and other jurisdictions. The department shall determine the in-state and total fleet miles to be used in computing the fee payment for the fleet. The department may evaluate and adjust the estimate in the application if it is not satisfied as to the correctness of the estimate.