399th Avenue in Belmont Township, South Dakota

399th Avenue in Douglas County is an unpaved unclassified road. It runs in a north-south direction and crosses 275th Street, SD Highway 44, 277th Street, 278th Street, 279th Street, 280th Street, 281st Street, 282nd Street, 283rd Street, 284th Street, 285th Street and US Highway 18. It ends in a cul-de-sac and connects Belmont Township, East Choteau Township and Lincoln Township.