399th Avenue in Gem Township, South Dakota

399th Avenue in Brown County is a gravel unclassified road. It runs in a north-south direction and crosses 137th Street, 138th Street, 139th Street, 142nd Street, 143rd Street and 144th Street. It ends in a cul-de-sac and connects East Rondell Township and Gem Township. 399th Avenue also exists in Cambria Township, Columbia Township, Liberty Township, Shelby Township and Greenfield Township.