S.D. Codified Laws § 7-3-4
Any bonded indebtedness of such original county shall be apportioned to each division ratably upon the basis of the last equalized assessment previous to the division thereof and each of such divisions shall be charged with, assume, and pay its just portion of such debt upon the basis of such apportionment; and each new division shall, as soon as organized as a county, issue its bonds to meet its portion of such bonded debt. Such bonds shall be made payable to the original county, shall bear the same rate of interest, be of similar tenor, and shall mature on the same date as the outstanding bonds of the original county on account of which the bonds of the new county are issued. The county commissioners of each new county shall annually levy and collect a tax to pay the interest on the bonds issued hereunder as it shall accrue and to meet and discharge the principal thereof at maturity, and the original county shall retain such bonds and not be allowed to dispose of or sell the same.
SDCL 7-3-4