The Bureau of Mines channel sampled and diamond drilled the Golden Zone Mine and nearby gold-copper deposits in 1950 and 1951. Difficult drilling conditions made sampling costs prohibitive; the work had to be stopped before enough data was obtained to estimate recoverable reserves. The Golden Zone Mine is near the southwestern end of a northeast-southwest-trending belt of compelx sulfide deposits, about 6 miles long, straddling the west fork of the Chulitna River in the healy quadrangle, south-central Alaska (fig. 1). The deposits are related to small diorite and diorite-porphyry stocks and dikes which intrude complexly interlayered sedimentary and volcanic rocks. Gold and silver, associated with arsenopyrite, pyrrhotite, chalcopyrite, sphalerite, and galena occur in altered zones in and along fractures, contacts, bedding planes, and other openings in the intrusives and the surrounding sedimentary and volcanic complex. The golden zone deposit is in fracture zones within a diorite-porphyry stock.