Mount Adams, known by some Native American tribes as Pahto or Klickitat, is a potentially active stratovolcano in the Cascade Range. It is the second-highest mountain in the U.S. state of Washington, trailing only Mount Rainier. Adams is a member of the Cascade Volcanic Arc, and is one of the arc's largest volcanoes, located in a remote wilderness approximately east of Mount St. Helens. The Mount Adams Wilderness comprises the upper and western part of the volcano's cone. The eastern side of the mountain is part of the Yakama Nation.