The highway system under the jurisdiction of Clay County is composed of 396 miles of county state aid highways, 347 miles of county roads, and 876 miles of township roads for a grand total of 1,619 miles.
Of these 1,619 miles, 1,342 miles are of gravel surfacing with the remainder bituminous surfaced. Clay County is responsible for the repair and maintenance of 335 structures on the state inventory list.