Gilbert, W.G., and Spencer, J.E., 1992, Geologic map of Cemetery Ridge, Clanton Hills, and westernmost Gila Bend Mountains, La Paz and Yuma Counties, Arizona [Turtleback Mtn., and Nottbusch Butte 7.5 min]: Arizona Geological Survey Open-File Report 92-04, 16 p., 1 sheet, scale 1:24,000. Location: Cemetery Ridge, Clanton Hills, Gila Bend Mts.,