Chapter 13: The Intermontane West

The Intermontane West

This week the topic is The Intermontane West.  True to its name, The Intermontane West region is located on the western side of the United States and is directly east of the Sierra Nevada Mountains, and west of The Rocky Mountain Region discussed last week.  The region does partially extend into Canada, but the vast majority of land it encompasses is in the United States.  On the U.S side, The Intermontane West includes portions of, Washington, Oregon, Idaho, Colorado, Arizona, New Mexico, and most of Nevada, and Utah.  Rehoboth Beach is a large distance away from The Intermontane West, but we will compare the two and look for a common link between the two areas.

First, we will compare the Climates of both areas as has become the tradition.  The Intermontane West is a very diverse region.  In fact, The Intermontane West actually includes 4 different climate realms: sub-humid, semi-arid, moderately arid, and extremely arid.  Local climate patterns are largely influenced by elevational differences similar to The Rocky Mountain Region.  In contrast, elevation differences are not a deciding factor in weather patterns for Rehoboth Beach because the area is rather flat, and does not feature mountainous terrain.   Air moving in from the pacific is a dominant influence on climate patterns in The Intermontane West.  Similarly, the Atlantic Ocean plays a big role in the climate, and weather of Rehoboth Beach.  The Sub-humid portion of The Intermontane West includes mountainous areas in Eastern Oregon, Washington, and Idaho.  The high elevation of the mountains result in westerly winds dropping precipitation as they flow over the mountain.  At higher elevations the precipitation often falls in the form of snow.  The semi-arid area includes most of the Columbia Plateau including the Palouse region.  The moderately arid area includes most of the Great Basin of Nevada and Utah, and is the largest area of the 4 separate climate realms that make up The Intermontane West.

Death Valley National Park

 Lastly, the extremely arid area includes the Mojave Desert and Death Valley.  The extremely arid realm gets less than 8 inches of rain each year.  Death valley is the driest place in North America, and receives less than 3 inches of precipitation on average annually.  This is a big difference from the annual amount of rain Rehoboth Beach experiences each year.  During storms, Rehoboth Beach can experience more rain in a day than Death Valley gets all year.  Death Valley, and the extremely arid realm receive little rain because they are located in what geographers call the "rain shadow".  A rain shadow is the area located behind a large mountainous area.  The wind blows in westward from the Pacific Ocean, and drops most of its precipitation as it flows up and over the Sierra Nevada Mountains.  By the time the wind makes it up and over, very little (If any) precipitation is left for the extremely arid realm.  Thus, a rain shadow is formed.  In contrast however, areas in the mountains of the sub-humid portion of The Intermontane West can receive as much as 150inches of precipitation on the western slopes a year.  150 inches of rain would more than triple the average annual rainfall Rehoboth Beach experiences.  The Intermontane West is a very diverse region, and features various unique and extreme climates.  Therefore, Rehoboth Beach and The Intermontane West do not have many similarities in terms of climate.

Federal Government land ownership as a percent by state

As the U.S expanded westward an interesting trend started occurring in The Intermontane West region.  Areas in The Intermontane West, and all states west of there, have much larger percentages of land under federal ownership than states east of The Intermontane West.  Most of the states in The Intermontane West have at least 40% of their land owned by the Federal Government.  In Nevada, the Federal Government owns 84.48% of the land.  This trend can be explained by a few things.  First, the federal government owned little land on the east coast and realized they should keep some under their control.  Second, the area is largely rural and unsuitable for large establishments; however it is suitable for federal uses such as military bases.  Lastly,  portions of the land under federal ownership are National Parks or Preserves.  East of The Intermontane West federal land holdings are much smaller.  In Delaware, The government only owns 2.04% of the land.  Rehoboth Beach, and Delaware as a whole, is mostly owned by people outside of the Government, as apposed to the large Federal Government land ownership in The Intermontane West.  This trend highlights a big difference between Rehoboth Beach, Delaware and The Intermontane West region.

Rehoboth Beach and The Intermontane West are two largely different areas.  Both places offer unique experiences to visitors, but the similarities between the two regions are few and far between.  Next week we will cover MexAmerica as we continue to move West across North America.  Rehoboth is not a part of MexAmerica so we will compare the two climates, and look for an additional similarity or difference like we did this week.

Until Next time,
William