Harrison County maintains 144 miles of paved roads and 792 miles of gravel road. In addition, there are over 160 miles of earth roads in the county. The Code of Iowa requires all counties to employ a licensed engineer to be in charge of the construction and maintenance of all roads under the county’s jurisdiction. The County Board of Supervisors fixes the terms of employment of the engineer. All employees of the Secondary Road Department are hired by the County Engineer, at the direction of the Board, to carry out the duties of the Department.