Geography of the United States York City, and includes the Florida peninsula. Areas further inland feature rolling hills, mountains, and a diverse collection of temperate and subtropical moist and wet forests. The Appalachian Mountains form a line of low mountains separating the eastern seaboard from the Great Lakes and the Mississippi Basin. The five Great Lakes are located in the north-central portion of the country, four of them forming part of the border with Canada, only Lake Michigan situated entirely within United States. The southeast United States, generally stretching from the Ohio River on south, includes a variety of warm temperate and subtropical moist and
Great Lakes Areas of Concern the contiguous United States' Pacific and Atlantic coastlines combined. The lakes are a system of transport and shipping, as well as a place of recreation. An Area of Concern must have at least "one beneficial use impairment which means that it has undergone a change in its chemical, physical, or biological integrity of a water body." These include: The Great Lakes Water Quality Agreement between the United States and Canada more specifically defines Areas of Concern as "geographic areas that fail to meet the general or specific objectives of the agreement where such failure has caused or is likely to