S.D. Codified Laws § 55-10A-24
Any transfer of custodial property as now defined in this chapter made before July 1, 1986 is validated notwithstanding that there was no specific authority in the Uniform Gifts to Minors Act of South Dakota for the coverage of custodial property of that kind or for a transfer from that source at the time the transfer was made.
This chapter applies to all transfers made before July 1, 1986 in a manner and form prescribed in the Uniform Gifts to Minors Act, except insofar as the application impairs constitutionally vested rights or extends the duration of custodianships in existence on July 1, 1986.
Sections 55-10A-1 and 55-10A-22, with respect to the age of a minor for whom custodial property is held under this chapter do not apply to custodial property held in a custodianship that terminated because of the minor's attainment of the age of eighteen after July 1, 1968, and before July 1, 1986.
SDCL 55-10A-24