Black Buttes was active during the mid-Pleistocene from 495,000 to 288,000 years ago, producing viscous, andesitic lava flows with a steep dip (the steepest angle of descent of a tilted bed or feature relative to a horizontal plane) that reach thicknesses of up to , though they were could actually be larger as they are covered by ice. Its most active eruptive period took place between 350,000 and 330,000 years ago.