Ohio Rev. Code § 307.11
When the county would be benefited, the board of county commissioners may make, execute, and deliver contracts or leases to mine iron ore, stone, coal, petroleum, gas, salt, and other minerals upon lands owned by such county, to any person complying with the terms prescribed by the board as to consideration, rights of way, and occupancy of ground for necessary purposes. All other matters of contract shall be such as the board deems most advantageous to the county.
Such contracts or leases shall be forfeited to the county for noncompliance with any of the terms of the contract, and shall not operate as a conveyance of the fee of any part of the realty. No contract or lease for the drilling or operation of a petroleum or gas well shall be valid for a longer term than forty years from the date of the contract or lease, and no contract or lease for the mining of iron ore, stone, coal, salt, or other minerals shall be valid for a longer term than fifteen years from such date. The consideration of such contracts and leases shall be a rental or royalty, payable at least once in each year to the county treasurer, who shall give a receipt for such amount, and be charged with it by the county auditor, with whom such receipts, contracts, and leases shall be deposited. The fund created by such payments shall be held and used for county purposes.
R.C. §307.11