Hoodoo Butte lies near the Santiam Pass area, in the eastern segment of the Cascade Range known as the High Cascades, which trends north-south. Constructed towards the end of the Pleistocene epoch, these mountains are underlain by more ancient volcanoes that subsided due to parallel north-south faulting in the surrounding region. In the region stretching south from Mount Jefferson to Santiam Pass, shield volcanoes dominate, forming a broad ridge with cinder cones. Eruptions at these vents have produced rocks with compositions ranging from basaltic andesite to andesite and basalt lavas. The majority of rock in the region consists of normally polarized material less than 730,000 years old.