The mountain range located in the northwestern United States is the Cascade Range. This volcanic mountain range extends from northern California, through Oregon and Washington, all the way into British Columbia, Canada. The Cascades include renowned peaks such as Mount Rainier and Mount St. Helens, known for their striking beauty and geological activity. The region is characterized by its diverse ecosystems, ranging from lush temperate rainforests to alpine environments, making it a popular destination for outdoor activities like hiking, skiing, and wildlife observation.