Metropolitan division

A county or group of counties within a metropolitan statistical area that contains an urban area with a population of at least 2.5 million. A metropolitan division consists of one or more main and secondary counties that represent an employment center or centers, plus adjacent counties associated with the main county or counties through commuting ties.

For more information on how metropolitan areas are delineated, see http://www.census.gov/population/www/estimates/metroarea.html.

A list of metropolitan areas and component counties is available.