Ash-flow Tuff 31. Outcrop of dacite tuff of Antelope Well (map unit dta), which is the only ash-flow tuff at Medicine Lake volcano. Exposure is on lower north flank of volcano just west of Lava Beds National Monument and 1.5 km east of Gold Digger Pass, in shallow depression north of road connecting Lava Beds National Monument to Gold Digger Pass. Photograph by Julie M. Donnelly-Nolan.