SDCL § 31-14-5: Bridge plans and specifications--Design requirements--Filing by county auditor.

A registered engineer retained by the board of county commissioners or the department shall prepare plans and specifications for bridge repair or construction work. Plans and specifications prepared by a registered engineer retained by the board of county commissioners shall conform to the design requirements of the American Association of State Highway and Transportation Officials. The plans and specifications, whether prepared by the department or by a registered engineer retained for that purpose, shall be forwarded to the proper county auditor who shall place them on file in the auditor's office. A copy shall be forwarded to the department for the department's records.