The Sourdough Mountains, also called Sourdough Ridge, is a mountain ridge on the northeast side of Mount Rainier in Mount Rainier National Park, Washington, United States. The range forms an L-shape, starting at Mount Fremont, running east to Dege Peak, turning north to Slide Mountain.
The ridge is a popular hiking destination, due to the excellent view of Mount Rainier and its proximity to roads and the Sunrise Visitor Center.