Search results
Results from the WOW.Com Content Network
The Central Great Plains are a prairie ecoregion of the central United States, part of North American Great Plains. The region runs from west-central Texas through west-central Oklahoma, central Kansas, and south-central Nebraska. It is designated as the Central and Southern Mixed Grasslands ecoregion by the World Wide Fund for Nature.
Map of major river basins. These are the major U.S. river basins in the U.S., as designated by the U.S. Water Resources Council. [1] Each of these river basins contain a number of smaller river basins.
The Atlantic Seaboard basin in eastern North America drains to the Atlantic Ocean; the Great Lakes-St. Lawrence basin in central and eastern North America drains to the Gulf of St. Lawrence on the Atlantic Ocean or to the Labrador Sea; the Gulf of Mexico basin in the southern United States drains to the Gulf of Mexico, a basin of the Atlantic ...
The term "United States," when used in the geographic sense, refers to the contiguous United States (sometimes referred to as the Lower 48, including the District of Columbia not as a state), Alaska, Hawaii, the five insular territories of Puerto Rico, Northern Mariana Islands, U.S. Virgin Islands, Guam, American Samoa, and minor outlying possessions. [1]
The physiographic regions of the contiguous United States comprise 8 divisions, 25 provinces, and 85 sections. [1] The system dates to Nevin Fenneman's report Physiographic Divisions of the United States, published in 1916. [2] [3] The map was updated and republished by the Association of American Geographers in 1928. [4]
Yet on the whole, a broadly extended surface of moderate relief so often prevails that the name, Great Plains, for the region as a whole is well-deserved. [9] The western boundary of the plains is usually well-defined by the abrupt ascent of the mountains. The eastern boundary of the plains (in the United States) is more climatic than topographic.
The Ogallala Aquifer (oh-gə-LAH-lə) is a shallow water table aquifer surrounded by sand, silt, clay, and gravel located beneath the Great Plains in the United States. As one of the world's largest aquifers, it underlies an area of approximately 174,000 sq mi (450,000 km 2) in portions of eight states (South Dakota, Nebraska, Wyoming, Colorado, Kansas, Oklahoma, New Mexico, and Texas). [1]
Shaded relief map of the United States, showing 10 geological provinces. The richly textured landscape of the United States is a product of the dueling forces of plate tectonics, weathering and erosion. Over the 4.5 billion-year history of the Earth, tectonic upheavals and colliding plates have raised great mountain ranges while the forces of ...