All real estate belonging to any county in this state, and not required for immediate public use, may be leased as hereinafter provided. Such real estate, except such as is located within the area of a cooperative grazing association and leased to such association, shall be offered for lease at public auction at the courthouse of the county within which such real estate is situated. If there be no courthouse, then at the building in which the office of the county auditor is located. The annual leasing date of such property shall be fixed by the board of county commissioners each year and advertised accordingly.
SDCL 7-30-1