Northwest Commonwealth

The Northwest Commonwealth was one of the thirteen areas of the pre-war United States of America. Created in the early 21st century, it was comprised of the former states or regions of Northern California, Washington, Oregon, Idaho, and Alaska, and bordered the Southwest, Northern, and Four States Commonwealth.

Background
Alaska was one of the major sites of fighting during the war with China, notably around the Anchorage Front Line. It was very important during the War because of the Trans- Alaskan Pipeline.

War in Alaska
In 2059, the United States establishes a significant military force to protect its oil interests in Alaska, in light of the ever dwindling oil reserves in the world, as well as increasing tensions with China. In the winter of 2066, the Americans' fears become reality as the Chinese military invades Alaska and takes over a significant portion of the land. Alaska becomes a war zone between the United States and China, furthering fears of nuclear apocalypse around the world as Power armor is developed and deployed. On January 10, 2077, the United States finally reclaims Alaska from the Chinese. The war between the two remained intense, ultimately leading to the Great War on October 23 of the same year.

Alaska Wasteland
The Brotherhood expanded and stopped through Alaska. They thought it was a great place to settle down, and formed a military network in the area.

Washington Wasteland
Unleashed viruses and irradiation have done strange things to the flora and fauna in the wastelands of Washington and northern Oregon. Blackened devastation is interspersed with wild, exotic, almost pre-historic vegetation and pockets of decaying urban ruins. Refugees from the major populations banded into smaller settlements and medieval-like townships. Isolated survivalists that are encountered remind one of Grizzly Adams. The Issaquah Nation controls the inland landscape.

Northwest Wasteland
There are a number of towns there, including Klamath and Arroyo.

Idaho Wasteland
The Great Khans could have abandoned the Mojave, and limped to Idaho, trying to sharpen it's claws once more.

Northern California Wasteland
A large portion of the Chosen One's journey was made in this region.

Alaska

 * Anchorage (Operation: Anchorage)
 * Chugach Overlook Air Force station (Operation: Anchorage)
 * Elmendorf Air Force Base (Operation: Anchorage)
 * Fire Island Air Force Station (Operation: Anchorage)
 * Juneau (mentioned in Fallout 3)

Northern California

 * Den (Fallout 2)
 * EPA (Fallout 2)
 * Modoc (Fallout 2)
 * Navarro (Fallout 2)
 * Sac-Town (Honest Hearts)
 * San Francisco (Fallout 2, Mentioned in Fallout 4 and Fallout 76)
 * Sierra Army Depot (Fallout 2)
 * Redding (Fallout 2)

Oregon

 * Arroyo (Fallout 2)
 * Forward Depot (Operation: Anchorage)
 * Klamath (Fallout 2)
 * Toxic Caves (Fallout 2)

Fort Willamette is a Brotherhood of Steel stronghold in northwest Oregon.

Washington

 * Seattle (Fallout Online, Fallout Extreme)
 * Capitol Hill (Fallout Extreme)
 * Troll Warren (Fallout Extreme)

Appearances
Parts of the Northwest Commonwealth appear in Fallout 2. Alaska appears in Operation: Anchorage Fallout 3 and the Fallout Bible, and a simulation of Anchorage can be seen in the Fallout 3 add-on Anchorage and is mentioned in Fallout: New Vegas and its add-on Honest Hearts. Fallout Extreme (which never made it out of concept) would've taken place partly in Alaska, Oregon and Washington as well.