SDCL § 31-14-23: Purchase of twelve months' supply of materials--Estimate by county highway superintendent--Specifications.

If it is deemed advisable by the board of county commissioners, the board may purchase material to be used in the construction of roads, bridges, and culverts, in quantities sufficient to meet the estimated demand of the county for the materials for the next succeeding twelve months. Before purchasing the materials, however, the board of county commissioners shall direct the county highway superintendent to prepare an estimate setting forth the needs of the county during the twelve months. The county highway superintendent shall prepare specifications of the quality of all materials. No patented material may be specified to the exclusion of unpatented material.