421st Avenue in Darlington Township, South Dakota

421st Avenue in Clark County is an unpaved unclassified road. It runs in a north-south direction and crosses 184th Street, SD Highway 28, 192nd Street and 193rd Street and ends at 195th Street, while the other end is a cul-de-sac. It connects Darlington Township and Rosedale Township. 421st Avenue also exists in Lincoln Township, Garfield Township and Woodland Township.