Though Three Fingered Jack does not have a high-level conduit-filling volcanic plug, its summit sits atop a pyroclastic cone. Another cone lies to the south of the major cone, and there are secondary craters on the sides, as well as radial dikes and volcanic plugs. Known subfeatures include two shield volcanoes, Maxwell Butte (less eroded than Three Fingered Jack) and Turpentine Peak, which have elevations of and , respectively. There are six additional known volcanic cones: Duffy Butte, at an elevation of ; Hogg Rock (a tuya), at an elevation of ; Marion Mountain, at an elevation of ; Red Butte, with an elevation of ; and Marion Peak and Saddle Mountain, which do not have elevations listed. Other shield volcanoes and cinder cones that were active during the Pleistocene epoch occur to the northwest and southwest.