County Highway 18 in Dewey Township, McPherson County, South Dakota

County Highway 18 in McPherson County is a gravel unclassified road. It runs in an east-west direction starting from 342nd Avenue and crosses 343rd Avenue, 344th Avenue, 347th Avenue and County Highway 13 and ends at 350th Street. It connects Dewey Township and Blaine Township. County Highway 18 also exists in Cleveland Township and Hillsview Township.