Several major cities and regional business centers in the continental United States lack Amtrak or some form of inter-city passenger rail service. Six of these metropolitan areas contain more than one million residents. Other than the service provided by the Alaska Railroad, there is no U.S.-based interstate passenger rail service outside of 46 of the contiguous states and the Canadian provinces of British Columbia, Ontario, and Quebec; there is no inter-city passenger rail service to the states of South Dakota or Wyoming.