81-4-210. Only purebred bulls to run at large -- limitation on time. It shall be unlawful for any person or persons, firm, company, or corporation to turn upon or allow to run at large on the public highways, open range, or national forest reserve within the state of Montana any bull other than a purebred bull of a recognized beef type; and no bull shall be turned upon or allowed to run at large upon any such public highways, open range, or national forest reserve between December 1 and June 1 of each and every year.