1935–1942
United States Geological Survey, 1937
United States Geological Survey, 1936
United States Geological Survey, 1980
United States Geological Survey, 1935
American 20th Century, 1965
United States Geological Survey, 1939
United States Geological Survey, 1938
United States Geological Survey
United States Geological Survey, 1941
United States Geological Survey, 1940
