Reed, John Calvin,  1930- <br/><br/>
The river and the rocks :  the geologic story of Great Falls and Potomac River Gorge / 
by John C. Reed, Jr., Robert S. Sigafoos, and George W. Fisher 
 - Washington, D.C :  United States Government Printing Office,  1980 
 - vii, 75 p. :  ill. ;  23 cm. 
 - U.S. Geological Survey bulletin ; 1471 .
<br/><br/> Edition of 1970 by United States Geological Survey and National Park Service 
<br/><br/>Bibliography: p. 74 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Geology--Great Falls of the Potomac (Md. and Va.)--Guidebooks<br/>Natural history--Great Falls of the Potomac (Md. and Va.)--Guidebooks<br/>Geology--Survey--Potomac (Md. and Va.)
<br/><br/><label>Subjects--Geographic Terms: </label><br/>Great Falls of the Potomac (Md. and Va.)--Guidebooks
<br/><br/><label>Dewey Class. No.: </label>557.52