S.D. Codified Laws § 27A-1-16
Any treatment facility in South Dakota may enter negotiations with appropriate personnel of a bordering state to develop a contract that conforms to the requirements of §§ 27A-1-12 to 27A-1-17, inclusive. A contract with a bordering state shall enable the temporary placement in South Dakota by a bordering state of a person who is on an emergency hold or who has been involuntarily committed due to mental illness or a substance use disorder as determined by the bordering state. Any person committed by a bordering state or on emergency hold from a bordering state and who is placed in a South Dakota facility continues to be in the legal custody of the bordering state and shall be returned to the bordering state before release from emergency hold or involuntary commitment. The bordering state's laws governing commitment criteria, length of commitment, hearings, reexaminations, and extension of commitment continue to apply to these bordering state residents. The State of South Dakota is not responsible for treatment costs, legal proceeding costs, or transportation costs. In all other aspects, a resident of a bordering state placed in a South Dakota facility is subject to the laws of South Dakota. A contract under §§ 27A-1-12 to 27A-1-17, inclusive, with a bordering state or bordering state governmental entity shall specify that responsibility for payment for the cost of care and transportation for persons under §§ 27A-1-12 to 27A-1-17, inclusive, remains with the contracting entity of the bordering state of which that person is a resident.
SDCL 27A-1-16