Topographic map, Lassen Volcanic National Park, California /
Geological Survey (U.S.)
Davis, E. P.,topographer.
Stevenson, R. G.
[Washington, D.C.] : U.S. Geological Survey,
1929.
Relief shown by contours and spot heights.
Contour interval 50 feet. Datum is mean sea level.
"Surveyed in 1925-1926."