S.D. Codified Laws § 41-3-14
It is a Class 2 misdemeanor for any person to obstruct any appointee or employee of the Department of Game, Fish and Parks who is engaged in assigned duties of gathering fish spawn, collecting or killing fish, or any other activities undertaken to carry out the department's duties and responsibilities of managing the fisheries resources of the state. It is a Class 2 misdemeanor for any person to place in public waters any logs or other debris or objects if such action may impede the accomplishment of assigned duties by departmental appointees or employees. It is a Class 2 misdemeanor for any person to move, handle, or disturb any net or other device used by department appointees or employees for the purpose of carrying out assigned duties.
SDCL 41-3-14