S.D. Codified Laws § 32-22-42.16
If a commercial operator of a vehicle on which is mounted hay grinding equipment is issued an oversize permit pursuant to §§ 32-22-41 and 32-22-42, the operator may move the vehicle from November first to March thirty-first, inclusive, upon any public highway during any time of the day or night if the vehicle is operated within one hundred miles of the business location of the commercial operator. However, no operator may move hay grinding equipment on the interstate highway between one-half hour after sunset and one-half hour before sunrise on the following day. The vehicle or the load may not exceed twelve feet in width. If the vehicle is operated during the period of day between one-half hour after sunset and one-half hour before sunrise, the vehicle shall display flashing or rotating white or amber lights at each side of the vehicle's widest extremity. The warning lights shall be clearly visible to any motorist approaching from the front or the rear. The annual fee for any oversized permit issued to a commercial operator of a vehicle on which is mounted hay grinding equipment is fifty dollars.
SDCL 32-22-42.16