S.D. Codified Laws § 27A-13-18.1
If the administrator of the Human Services Center has treated a patient as from a county determined to be the county of the patient's residence by the committing board of mental illness and that county has appeared before the committing board to contest its determination of residence in the manner provided in this title, and the state's attorney or county commissioners of the county claim that the patient is not a proper charge against the county and that the patient is a proper charge against the state at large because the patient is not a resident of the state, that county may appeal the committing board's determination of the patient's residence to the circuit court. Notice of such appeal shall be served upon the attorney general within thirty days from the date of the finding of residence by the committing board of mental illness. Upon the filing of such an appeal, the circuit court shall conduct a trial de novo and determine, by a preponderance of evidence, the residence of such patient and thereupon determine whether he is a proper charge against the county or the state at large. Such determination is conclusive unless an appeal is taken therefrom in the manner provided by law for appeals in civil actions.
SDCL 27A-13-18.1