🏔️ Simcoe Mountains

The Simcoe Mountains Volcanic Field, sometimes called the Simcoe Highlands, is a group of lava flows and extinct cinder cones located to the east of the Cascade Range in south-central Washington, United States. The mountains lie within Klickitat and Yakima Counties with the northern half making up part of the Yakama Indian Reservation. Although the volcanic field is located near the Cascade Arc of volcanoes, it is an intraplate volcanic field rather than having activity sourced from the Cascadia subduction zone. The last known eruption was about 631,000 years ago.