S.D. Codified Laws § 32-5-8.1
Each trailer or semitrailer pulled by a noncommercial motor vehicle on which the license fees were paid pursuant to § 32-5-6.3 shall have an identification plate displayed in a conspicuous manner. The fee for the identification plate is ten dollars. The identification plate is valid for the useful life of the trailer or semitrailer. However, if the title to the trailer or semitrailer is transferred, the new owner shall within forty-five days of the date of transfer make application to the department for a new identification plate. All revenue raised by the fees shall be placed in the license plate special revenue fund. However, no identification plate may be displayed on a recreational vehicle as defined in § 32-3-1. A recreational vehicle shall be licensed pursuant to § 32-5-8.
SDCL 32-5-8.1