Columbia subject headings:
Geochemical prospecting--California--El Dorado County--Maps.
Maps.
Sediments (Geology)--California--El Dorado County--Maps.
Harvard subject headings:
El Dorado County (Calif.)--Maps.
Geochemical prospecting--California--El Dorado County--Maps.
Pyramid Roadless Area (Calif.)--Maps.
Princeton subject headings: