Sub-Metropolitan Cities are urban areas that are smaller than major metropolitan cities but still exhibit significant economic, social, and cultural activities. These cities often serve as important regional hubs, providing services and opportunities for surrounding rural and suburban areas. They typically have a diverse population and a mix of residential, commercial, and industrial zones. These cities may have their own local governments and infrastructure, including schools, hospitals, and transportation systems. Examples of Sub-Metropolitan Cities include Boulder, Colorado and Madison, Wisconsin, which offer a blend of urban amenities while maintaining a smaller-town feel.