It is thought to be the result of the North American Plate passing over a hotspot, similar to the one feeding the Hawaiian Islands, known as the Anahim hotspot. The only real separate volcanic peak associated with the Rainbow Range is Anahim Peak which sits on its northeast flank. Other peaks in the range are other high eroded remnants of the shield, including Beef Peak, TaiaTaeszi Peak, Mount MacKenzie and Tsitsutl Peak 2,495 m (8,186 ft), which is the highest summit of the Rainbow Range.