Mich. Comp. Laws § 462.30
Every common carrier doing business in this state, or which shall hereafter do business in this state, and every person, firm or corporation owning property in this state which is used for common carrier purposes, shall on or before the first day of May, 1918, and on or before the same day in each year thereafter, make and transmit to the commission at its office in Lansing a full and true statement, under oath of the proper official of such carrier of the financial and operating transactions of such carrier relative to the state of Michigan for the year ending the thirty-first day of December preceding, which statement for the state of Michigan shall be similar in character and detail to the annual report, if any, required to be made by such carriers to the interstate commerce commission. The said commission shall cause to be made suitable blanks at the expense of the state and forward the same to such common carrier, upon which to make reports required by this act. The said railroad commission may require of such common carrier, subject to the provisions of this act, any other or additional information relating to the management of such carrier and to the condition of its respective property utilized for common carrier purposes and such other subjects as in its judgment may be necessary in order to gain full information in regard thereto. Every common carrier doing business in this state shall, when so ordered by the commission, report to the railroad commission its earnings and income statement for the period designated in such order, and the proper blanks for that purpose shall be furnished by the commission.
MCL 462.30