They usually consist of farmland, light suburban development or small towns and are classified as having an average of 100 people per square mile. In most instances, this is the type of land development that occurs as cities expand. Finally, non-urban areas are regions such as central Montana and western Maine, where only ten people or less live per square mile. A Bumper Crop of Brand New Homes Biting the Hand that Feeds Us Based upon satellite measurements of city lights, this image is a map of the urban population density of North America. Red yellow and green are urban areas, and blue is peri-urban.
Most major cities are in level areas along an ocean bay, large lake, or navigable river.