The Markagunt Plateau is part of the High Plateaus geologic province, in the Colorado Plateau and at its margins with the Basin and Range Province. It is a wide fault-bounded block and the basement underneath the volcanoes is formed by various Cretaceous to Miocene sedimentary or volcanic rocks. Volcanism in the region has been ongoing for the last 5 million years. The volcanism is considered to be intraplate and unrelated to either mantle plumes or subduction.