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 is the largest lake that is entirely within one country. The Great Lakes began to form at the end of the last glacial period around 14,000 years ago, as retreating ice sheets exposed the basins they had carved into the land which then filled with meltwater. The lakes have been a major source for transportation, migration, trade, and fishing, serving as a habitat to a large number of aquatic species in a region with much biodiversity. The surrounding region is called the Great Lakes region, which includes the Great Lakes Megalopolis. Though the five lakes lie in separate basins, they