When improvements have been constructed in accordance with a permit, as provided in § 7-31-7, and the owner of the improvements ceases to lease such lands, he may remove such improvements as are physically capable of removal within ninety days of the termination of his lease. If such improvements are not removed within the said ninety days, or sold within said period to a lessee or purchaser of the lands, they shall become the property of the county.
SDCL 7-31-8