These areas contain some spectacular scenery as well, as evidenced by such national parks as Yosemite and Mount Rainier. West of the Cascades and Sierra Nevada is a series of valleys, such as the Central Valley in California and the Willamette Valley in Oregon. Along the coast is a series of low mountain ranges known as the Pacific Coast Ranges. Much of the Pacific Northwest coast is inhabited by some of the densest vegetation outside of the Tropics, and also the tallest trees in the world (the Redwoods).

Answer this question, if possible (if impossible, reply "unanswerable"): What are the skinniest trees in the world?
unanswerable