S.D. Codified Laws § 32-25-12 (2026)
In urban areas which are not zoned or posted as provided in § 32-25-7, the maximum lawful speed shall be twenty-five miles per hour. A violation of this section is a Class 2 misdemeanor.
Source: SDC 1939, § 44.0303 (5) to (7); SL 1941, ch 187 , § 1; SL 1955, ch 168 ; SL 1959, ch 251 , § 1; SDC Supp 1960, § 44.0303 (6) (a); SL 1970, ch 175 , § 9; SL 1972, ch 182 ; SL 1989, ch 255 , § 133.