The commissioner of revenue shall annually compile a list of railroad operating property which is sold or otherwise becomes nonoperating property. On or before December 15 in each year the commissioner shall certify the lands for taxation to the auditors of the counties in which such lands lie. At the same time the commissioner shall obtain lists of lands reverting to and being used as operating property by the railroad companies by reason of the forfeiture of contracts, and certify the same to the county auditors, who shall thereupon remove such lands from the tax lists; but nothing herein shall be construed to relieve such forfeited lands from any lien for taxes or assessments accruing thereon during the life of such contract. The railroad companies shall report such sales and forfeitures to the commissioner of revenue December 1 in each year, and at other times when the commissioner requires. All forfeited lands not so reported shall be held for all taxes accruing thereon.