The history of the formation of the Cascade Mountains dates back millions of years ago to the late Eocene Epoch. With the North American Plate overriding the Pacific Plate, episodes of volcanic igneous activity persisted. Glacier Peak, a stratovolcano that is north-northeast of White Mountain, began forming in the mid-Pleistocene. Due to Glacier Peak's proximity to White Mountain, volcanic ash is common in the area and provides fertile soil for an abundance of wildflowers.