The secretary has the power to grant concessions in [the] state parks and recreation areas upon such rentals, fees or percentage of income or profits as he may prescribe, but not for a longer period than thirty years. All concessions shall be evidenced by a written contract, the faithful performance of which shall be secured by such bond as the secretary may prescribe. No contract granting a concession shall be effective until it has been approved by the state board of finance. History: Laws 1935, ch. 57, § 9; 1941 Comp., § 4-109; 1953 Comp., § 4-9-9; Laws 1961, ch. 114, § 1; 1963, ch. 98, § 9; 1973, ch. 81, § 1; 1977, ch. 254, § 19; 1987, ch. 234, § 16.