The Western United States (also called the American West, the Far West, and the West) is the region comprising the westernmost states of the United States. As American settlement in the U.S. expanded westward, the meaning of the term the West changed. Before about 1800, the crest of the Appalachian Mountains was seen as the western frontier. The frontier moved westward and eventually the lands west of the Mississippi River were considered the West.
The U.S. Census Bureau’s definition of the 13 westernmost states includes the Rocky Mountains and the Great Basin to the Pacific Coast, and the mid-Pacific islands state, Hawaii. To the east of the Western United States is the Midwestern United States and the Southern United States, with Canada to the north, and Mexico to the south.
The West contains several major biomes, including arid and semi-arid plateaus and plains, particularly in the American Southwest; forested mountains, including three major ranges, the Sierra Nevada, the Cascades, and Rocky Mountains; the long coastal shoreline of the American Pacific Coast; and the rainforests of the Pacific Northwest.
Defining The West
The Western U.S. is the largest region of the country, covering nearly half the land area of the contiguous United States. It is also the most geographically diverse, incorporating geographic regions such as the temperate rainforests of the Northwest, the highest mountain ranges (including the Rocky Mountains, the Sierra Nevada, and the Cascade Range), numerous glaciers, and the western edge of the Great Plains. It also contains the majority of the desert areas located in the United States. The Mojave and Great Basin deserts lie entirely within the Western region, along with parts of the Sonoran and Chihuahuan deserts (the latter extends significantly into Texas). Given this expansive and diverse geography it is no wonder the region is difficult to specifically define. Sensing a possible shift in the popular understanding of the West as a region in the early 1990s, historian Walter Nugent conducted a survey of three groups of professionals with ties to the region: a large group of Western historians (187 respondents), and two smaller groups, 25 journalists and publishers and 39 Western authors. A majority of the historian respondents placed the eastern boundary of the West east of the Census definition out on the eastern edge of the Great Plains or on the Mississippi River. The survey respondents as a whole showed just how little agreement there was on the boundaries of the West. (Wikipedia)