Minn. Stat. § 385.13: PUBLIC FUNDS KEPT SEPARATE.

The public funds shall at all times be kept separate from any private funds of the treasurer or any private person, and all amounts found at any time in any of the county treasuries of the state, or officially deposited by the county treasurers, shall be deemed public funds, and, if in excess of the amount properly called for by the auditor's and treasurer's books and accounts, shall be turned over by the county board or by the state auditor to the county revenue fund.