Whenever any person, firm, or corporation has been granted a lease or leases and has not tested or prospected the land so leased and a mistake has been made in the description of the land, there may be substituted therefor other land for that leased, under such rules and regulations as may be prescribed by the commissioner of school and public lands; provided however, that such application for such correction must be made within six months from the date of the lease.
SDCL 5-7-31