Blue Mountains (Oregon)

The Blue Mountains are a mountain range in the western United States, located largely in northeastern Oregon and stretching into southeastern Washington. The range has an area of , stretching east and southeast of Pendleton, Oregon, to the Snake River along the Oregon-Idaho border. The Blue Mountains cover seven counties in Oregon and Washington; they are Union, Umatilla, Grant, Baker, and Wallowa counties in Oregon, and Walla Walla, Columbia and Garfield counties in Washington. They are home to the world's largest organism and fungal mycelial mat, the Armillaria solidipes.