S.D. Codified Laws § 7-1-64

Beginning at a point where the township line between townships ninety - five and ninety - six north intersects the boundary line between the states of South Dakota and Iowa, thence west and along the township line between townships ninety - five and ninety - six north, to the northwest corner of township ninety - five, range fifty, west of the fifth principal meridian; thence south and along the range line between ranges fifty and fifty - one west, to the boundary line between the states of South Dakota and Nebraska; thence southeasterly and along said last mentioned state line to its intersection with the boundary line between the states of South Dakota and Iowa; thence northerly and along the boundary between the states of South Dakota and Iowa, to the place of beginning.

Source: SL 1863-4, ch 14, § 1; SL 1870-1, ch 10, § 1; SD SenJRes 4, 1905; Act of Congress approved March 1, 1905, ch 1295, 33 Stat. 820; SL 1907, ch 245, § 1; SDC 1939, § 12.0165.