S.D. Codified Laws § 5-18A-3
Methods of awarding contracts
Unless otherwise authorized by law, each contract for supplies, services, and construction shall be awarded by one of the following methods:
(1) Competitive sealed bids as provided in § 5-18A-5 ;
(2) Competitive sealed proposals as provided in §§ 5-18A-6 and 5-18A-7 ;
(3) Small purchases as provided in § 5-18A-11 ;
(4) Sole source procurement as provided in § 5-18A-8 ; or
(5) Emergency procurement as provided in § 5-18A-9 .
Source: SL 2010, ch 31, § 4.