S.D. Codified Laws § 32-5-45
Section 32-5-16.1 applies to all mobile homes not previously registered in this state. However, a mobile home owned by a nonresident coming into this state from another state, a mobile home purchased and owned by a member of the armed forces while on duty in the United States and a mobile home purchased in another state by a resident other than a dealer licensed pursuant to chapter 32-7A are exempt from the additional license fee to the extent of a similar and equal amount of registration tax, sales, use or state excise tax as has been paid in another state by the current applicant. The county treasurer shall require of applicants from other states and residents who have purchased a mobile home in another state, making application for registration of a mobile home in this state a certificate of a licensed dealer, bill of sale, receipt, or other tangible evidence that a similar and equal amount of tax has been paid by the current applicant. If sufficient proof is not furnished, the county treasurer shall collect an additional or full amount to equal the South Dakota rate of tax.
SDCL 32-5-45