[With regard to any county which is required to operate on a countywide system of road administration as described in Section 19-2-3, this section shall read as follows:]
Any county is authorized and empowered to purchase and hold, or to lease, any land containing gravel, sand, clay, chert or other road building material to be used in the construction and maintenance of roads, and to sell off any of such road building material in excess of its own needs. Such land or lease is to be held in the name of the county. Such land or lease is to be paid for out of the proper county fund, and any funds arising from the sale of material are to be turned back into the fund from which the purchase price was made. The necessary roads or other means to reach and use the property aforesaid may be constructed and maintained by the county.