77-6-404. Proof of termination of pledge or mortgage to be filed. The lessee of any grazing or agricultural lease of or leasehold interest in state lands which is pledged or mortgaged as provided in this part shall, within 30 days after payment of the indebtedness secured thereby or within 30 days after the pledge agreement is terminated or the leasehold interest is released from the mortgage, file with the department proof of that fact.