S.D. Codified Laws § 31-12-27.1
Any county may contract with residents served by county roads for the construction, maintenance, and improvement of county roads or any portion thereof serving county residents. If the board of county commissioners, upon a petition by a resident within the county, filed in the office of the county auditor of the county, determines that it is in the best interest of the petitioner and in the public interest that the petitioner enter into an agreement in writing with the board of county commissioners of such county for the construction, maintenance, or improvement of county roads or any portion thereof, the board of county commissioners may enter into an agreement in writing with the petitioner to construct, maintain, or improve any such county road or portion thereof to be specifically designated, at and for a price to be paid to the county to be expressed in the agreement. If the board of county commissioners determines that it is in the public interest to enter into such an agreement, the board may do so and the county may, by and through its highway department and with the personnel and equipment thereof or by privately let contract pursuant to § 5-18A-9, perform or cause to be performed such construction, maintenance, and improvement specified in the written agreement under the supervision and control of the county highway superintendent. The prices specified in the contract shall be paid to the county or if privately let, to the person performing the work by the resident petitioning upon estimates certified to by the county highway superintendent.
SDCL 31-12-27.1