Blue Mountains (Pacific Northwest)

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Blue Mountains
Baker City, Oregon, with the Blue Mountains in the background, seen from the National Historic Oregon Trail Interpretive Center observatory
Highest point
Peak	Rock Creek Butte[1][2]
Elevation	9,106 ft (2,776 m)
Coordinates	44°49′00″N 118°06′13″W / 44.81667°N 118.10361°W / 44.81667; -118.10361[3]
Dimensions
Area	15,000 sq mi (39,000 km2)
Geography
Country	United States
States	Oregon, Washington

The Blue Mountains are a mountain range in the northwestern United States, located largely in northeastern Oregon and stretching into extreme southeastern Washington. The range has an area of about 15,000 square miles (39,000 km²), stretching east and southeast of Pendleton, Oregon, to the Snake River along the Oregon–Idaho border.^[4]

The Blue Mountains cover ten counties across two states; they are Union, Umatilla, Grant, Baker, Wallowa and Harney counties in Oregon, and Walla Walla, Columbia, Garfield and Asotin counties in Washington.^[5] The Blue Mountains were named after the color of the mountains when seen from a distance and the blue hue imparted by the smoke of forest and range fires set by Indigenous people as management tools in the fall.^[6]

The Blue Mountains are unique as the home of the world's largest living organism, a subterranean colonial mycelial mat of the fungus Armillaria ostoyae.^[7]