vi, 64 p., 15 leaves of plates: ill., maps (some col.); 29 cm
Geology and ore deposits of the Breckenridge mining district, Colorado / by T.S. Lovering.
Geological Survey U.S.; Professional paper; 176
Bibliography Note: Includes bibliographical references and index
5 maps in pocket
Washington D.C. : U.S. Govt. Print. Off., 1934