A group of cinder cones near Pleistocene Burney Mountain volcano, including Twin Buttes to the SE, is considered to be of Holocene age (Miller, 1989). The cones are part of are area of extensive Quaternary volcanism north of the Lassen volcanic field. Clynne (1994 pers. comm.) assigned an age of latest Pleistocene or early Holocene to the youngest volcanism in this area. Blocky, partially unvegetated lava flows extend to the north from North and South Twin Buttes, which are located at the SE foot of the Burney Mountain lava dome complex.