Which States Are In The Pacific Northwest?

The rugged Oregon coastline.
The rugged Oregon coastline.

The Pacific Northwest, sometimes referred to as Cascadia, is a region in western North America and bound to the east by Cascade Mountain Range and to the west by the Pacific Ocean. Although there is no official boundary defining the geographical region, the area includes the Candian province of British Columbia and the US states of Washington, Idaho, and Oregon. The coastal region of the Pacific Northwest is the Northwest Coast while the Northwest Plateau is the inland region. The largest metropolitan area in the region is Washington’s Greater Seattle with a population of 3.8 million residents. One of the major aspects of the Pacific Northwest is the international border between the United States and Canada.

The US States in the Pacific Northwest

Although the definition of Pacific Northwest varies and even the residents of this region have not agreed on the exact boundary, the common definition includes only three US states in the region, namely Idaho, Oregon, and Washington. These three regions are also part of the informal geographic region of the United States known as the Northwestern US. In broader terms, the region encompasses Alaska, Yukon, California, western Montana and parts of Wyoming. Here are the three states that are exclusively in the Pacific Northwest.


The state of Washington is the extreme northwestern state in the contiguous US, bordered by Idaho to the west and to the south by Oregon. It is one of the states in the Northwestern United States. Washington is bisected from north to south by high mountains of the Cascade Range, dividing the state into Western and Eastern Washington. The largest metropolitan area in the Pacific Northwest is Washington’s Greater Seattle, with a population of over 3.8 million people. However, Washington is the smallest of the three Pacific Northwestern states with an area of approximately 71,368 square miles.


The state of Idaho is situated in the Northwestern region of the US, bordered by Montana to the east and northeast, Wyoming to the east, Utah and Nevada to the south, and Oregon and Washington to the west. Idaho is the US 14th largest state and the second largest in the Pacific Northwest after Oregon with an area of approximately 83,569 square miles. The state is divided into several distinct and geographic regions with the panhandle closely linked to Eastern Washington.


By common definition, Oregon is the largest state in the Pacific Northwest region. It is located on the West Coast of the US, bordered by Washington to the north and Idaho to the east. Oregon is the largest of the three Northwestern states and the 9th largest with an area of approximately 98,381 square miles. It is the 27th most populous with a population of 4.2 million people. The Portland metropolitan area is the second-largest metropolitan area in the Pacific Northwest with a population of 3.1 million people.


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