Should the lessee for any reason, except strikes or inability to mine or dispose of output without loss, suspend mining operations upon the lands included in a lease, or upon any contiguous lands operated by the lessee in connection therewith, for a period of six months, or should the lessee for any reason suspend mining operations upon the lands included in a lease or in such contiguous lands for a period of twelve months, the department may, at its option, cancel the lease, first giving thirty days' notice in writing to the lessee.
The lessee shall have the right to terminate the lease after thirty days' written notice to the department and the payment of all royalties and rentals then due.