House Mountain is a shield volcano in Arizona's Coconino National Forest, between Sedona's Red Rock Country and the Verde Valley. Formed by eruptions about 13 to 15 million years ago along the edge of the ancient Mogollon Rim, its basalt cap preserved older layers such as the Schnebly Hill Formation and a thin band of Fort Apache Limestone. As the Mogollon Rim slowly retreated over time, its edge moved several miles from the summit. Named for a rocky formation that resembles a house from the valley below, House Mountain remains both a prominent hiking destination and a vivid example of how volcanism and erosion shaped central Arizona.