Castle Rock is a city in Cowlitz County, Washington, United States. Located between the Willapa Hills and the western base of Mount St. Helens, Castle Rock is at the heart of Washington timber country in the Pacific temperate rain forest. Castle Rock is part of the Longview, Washington Metropolitan Statistical Area; the population was 2,446 as of the 2020 census.
AdCancel Free on Most Hotels. Trips Made Easier and More Flexible. Easy to Plan and Book. Intuitive Trip Planning Allows You to Get More Travel with Less Stress.