South Dakota Codified Laws
Chapter 08 - Restoration Of Things Improperly Obtained
Section 20-8-2 - Demand not required for obligation to restore--Notice of mutual mistake required.

20-8-2. Demand not required for obligation to restore--Notice of mutual mistake required.
The restoration required by §20-8-1 must be made without demand except where a thing is obtained by mutual mistake, in which case the party obtaining the thing is not bound to return it until he has notice of the mistake.

Source: CivC 1877, §978; CL 1887, §3602; RCivC 1903, §1296; RC 1919, §800; SDC 1939, §47.0306.