For the purpose of ascertaining the amount of tax due and payable under this article, it shall be the duty of all producers to transmit to the department, on or before the twentieth day of the month next succeeding the month in which the tax accrues, a return upon the forms provided by the department. The return shall show the month or period covered, the total number of tons of each type of severed material sold from each production unit operated, owned, or controlled by the producer in each county during the period covered, the amount of the tax due, and such other information as the department may reasonably require to allocate the tax between raw materials severed and finished products sold, as the case may be in particular counties. The return shall be signed by the producer and shall be accompanied by the full amount of the tax shown to be due in good and immediate funds. A copy of the severance tax return shall be made available to any county commission receiving a portion of the tax paid upon request by the county commission.