High Plains (United States)

The High Plains are a subregion of the Great Plains. They are the western part of the Great Plains before the region reaches the Rocky Mountains.

The High Plains are in southeastern Wyoming, southwestern South Dakota, western Nebraska, eastern Colorado, western Kansas, eastern New Mexico, western Oklahoma, and south of the Texas Panhandle.:File:Level III ecoregions, United States.png They are mostly in the Western United States, but also partly in the Midwest states of Nebraska, Kansas, and South Dakota.

Geologically, the high plains are caused by the same process as caused the Rockies. The cause is the westward movement of North America away from Eurasia, which has been going on for over 100 million years. As the continent moved west, it subducted plates under the western side, and stretched out its eastern side. This explains why the western states all have some mountainous terrain, and the eastern states in the south are so low-lying.Elsewhere on this wiki, we explain how the Alleghanian and Appalachian Mountains in the east are the product of a much earlier period in the history of the Earth.

From east to west, the High Plains rise in elevation from around  to over . The High Plains has a "cold semi-arid" climate—Köppen BSk—they get between  of precipitation annually.

Due to low moisture and high elevation, the High Plains get extremes of temperature. The temperature range from day to night is usually , and 24-hour temperature shifts of  are possible.

In Browning, Montana from January 23, 1916 to January 24, 1916, the temperature fell from . This is the world record for the greatest temperature change in 24 hours. The region is known for the steady, and sometimes intense, winds that come from the west. These add a considerable wind chill factor in the winter.  The development of wind farms in the High Plains is one of the latest areas of economic development.

The High Plains has one of the lowest population densities of any region in the continental United States; Wyoming, for example, has the second lowest population density in the country after Alaska.

 References 

Category:Geography of the United States