The river and the rocks : the geologic story of Great Falls and Potomac River Gorge - Reed, John Calvin, 1930-; Sigafoos, Robert Sumner, 1920-; Fisher, George Wescott, 1937-; Geological Survey (U.S.). (Washington, D.C : United States Government Printing Office, 1980)
Edition of 1970 by United States Geological Survey and National Park Service
Bibliography: p. 74
Keywords: Geology -- Great Falls of the Potomac (Md. and Va.) -- Guidebooks; Natural history -- Great Falls of the Potomac (Md. and Va.) -- Guidebooks; Geology -- Potomac (Md. and Va.) -- Survey; Great Falls of the Potomac (Md. and Va.) -- Guidebooks