TY - MAP ID - 135875857 TI - Geologic sections of the East Calhoun mine and detailed section of the Wood 520 raise, East Calhoun mine, Central City district, Gilpin County, Colorado PY - 1957 PB - Washington (D.C.) U.S. Geological Survey DB - UniCat UR - https://www.unicat.be/uniCat?func=search&query=sysid:135875857 AB - ER -