South Dakota Codified Laws
Chapter 11 - Revision Of Contracts
Section 21-11-1 - Fraud or mistake as ground for revision.

21-11-1. Fraud or mistake as ground for revision.
When through fraud or mutual mistake of the parties, or a mistake of one party which the other at the time knew or suspected, a written contract does not truly express the intention of the parties, it may be revised on the application of a party aggrieved so as to express that intention, so far as it can be done without prejudice to rights acquired by third persons, in good faith and for value.

Source: CivC 1877, §2004; CL 1887, §4637; RCivC 1903, §2349; RC 1919, §2020; SDC 1939 & Supp 1960, §37.0601.