Yankee Creek

Past Producer in Alaska, United States with commodities Gold, Silver

Geologic information

Identification information

Deposit ID 10002581
MRDS ID A015018
Record type Site
Current site name Yankee Creek
Related records 10258159

Geographic coordinates

Geographic coordinates: -156.36824, 63.00861 (WGS84)
Relative position Yankee Creek is a north-northeast-flowing tributary to the upper Innoko River. Only the lower 4.5 miles of Yankee Creek are in the Ophir quadrangle; the rest of it flows through the Iditarod quadrangle. Mining activity occurred in both quadrangles. The junction of Yankee Creek and the Innoko River is approximately 8 miles southeast of the town of Ophir. The coordinates are for the approximate midpoint of mining activity along Yankee Creek in the Ophir quadrangle; it is near a landing strip and cabins marked on the U.S. Geological Survey Ophir A-1 topographic map (1954, minor revisions 1966), in sec. 3, T. 29 S., R. 13 E., Kateel River Meridian. Yankee Creek corresponds to localities 24 and 25 of Cobb (1972 [MF 367]). This location is accurate.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Silver Secondary

Materials information

Materials Type of material
Gold Ore

Mineral occurrence model information

Model code 119
USGS model code 39a
BC deposit profile C01. C02
Deposit model name Placer Au-PGE
Mark3 model number 54

Host and associated rocks

  • Host or associated Host
    Rock type Unconsolidated Deposit > Gravel
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Shale
  • Host or associated Host
    Rock type Sedimentary Rock > Clastic Sedimentary Rock > Sandstone

Nearby scientific data

(1) -156.36824, 63.00861

Comments on the geologic information

  • Geologic Description = The bedrock in the vicinity of Yankee Creek is slate, sandstone, and decomposed igneous rock (Mertie, 1936); the area also contains Cretaceous or Tertiary rhyolitic dikes and alkali-calcic monzonite plutons. These intrusive rocks are the likely source of gold in Yankee Creek (Bundtzen and others, 1987). Only the lower 4 1/2 miles of Yankee Creek are in the Ophir quadrangle; extensive mining along Yankee Creek also occurred in the Iditarod quadrangle.? Gold is found in the coarse gravels; in 1911, these gravels were about 8 feet thick and buried under 1 to 3 feet of muck and silt (Maddren, 1911). Bundtzen and others (1987) report that the gold is 849.6 fine, with 129.5 parts silver, and 20.0 parts impurities. Smith (1941) reports an average gold fineness of 882.? Heavy minerals identified in pan concentrates from lower Yankee Creek include magnetite, ilmenite, magnesiochromite, scheelite, and free gold (Bundtzen and others, 1987). Marten Gulch, a locally-named tributary to Yankee Creek in the Ophir quadrangle, contained magnetite, ilmenite, siderite, hornblende, hypersthene, eckermanite, and hidalgoite (a lead- arsenic sulfate) (Bundtzen and others, 1987).? Yankee Creek was first prospected during the winter of 1908-1909, and mining began in 1909 (Maddren, 1910; Maddren, 1911). Mining was nearly continuous from 1910 until 1940 (Cobb, 1976 [OFR 76-576]). Williams (1950) and Saunders (1960) report mining along Yankee Creek in 1950 and 1959.? A conservative estimate of production from Yankee Creek between 1909 to 1968 and 1981 to 1986 is 62,500 ounces of gold and 12,650 ounces of silver (Bundtzen and others, 1987).
  • Age = Quaternary. The source(s) of the placer gold probably are the Cretaceous or Tertiary rhyolitic dikes and monzonite plutons in the area (Bundtzen and others, 1987).

Economic information

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic

Mining district

District name Innoko

Comments on the production information

  • Production Notes = A conservative estimate of production from Yankee Creek between 1909 to 1968 and 1981 to 1986 is 62,500 ounces of gold and 12,650 ounces of silver (Bundtzen and others, 1987).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A015018
USGS Alaska Resource Data File ARDF OP021

Bibliographic references

  • Deposit

    Maddren, A.G., 1911, Gold placer mining developments in the Innoko-Iditarod region: U.S. Geological Survey Bulletin 480, p. 236-270.

  • Deposit

    Mertie, J.B., Jr., 1936, Mineral deposits of the Ruby-Kuskokwim region, Alaska: U.S. Geological Survey Bulletin 864-C, 115-245.

  • Deposit

    Williams, J.A., 1950, Mining operations in the Fairbanks district and Innoko and Koyukuk precincts: Alaska Territorial Department of Mines Miscellaneous Report 194-13, 20 p.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Ophir quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-367, 1 sheet, scale 1:250,000.

  • Deposit

    Cobb, E.H., 1973, Placer deposits of Alaska: U.S. Geological Survey Bulletin 1374, 213 p.

  • Deposit

    Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction material) in the Iditarod and Ophir quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-576, 101 p.

  • Deposit

    Chapman, R.M., Patton, W.W., and Moll, E.J., 1985, Reconnaissance geologic map of the Ophir quadrangle, Alaska: U.S. Geological Survey Open-File Report 85-203, 1 sheet, 1:250,000 scale.

  • Deposit

    Bundtzen, T.K., Green, C.B., Deagen, J., and Daniels, C.L., 1987, Alaska's mineral industry, 1986: Alaska Division of Geological and Geophysical Surveys, Special Report 40, 68 p.

  • Deposit

    Maddren, A.G., 1910, The Innoko gold-placer district, Alaska, with accounts of the central Kuskokwim valley and the Ruby Creek and Gold Hill placers: U.S. Geological Survey Bulletin 410, 87 p.

  • Deposit

    Saunders, R.H., 1960, Itinerary report on a trip to the Flat and Ophir Districts: Alaska Territorial Department of Mines Itinerary Report 64-2, 15 p.

Comments on the references

  • Primary Reference = Cobb, 1976 (OFR 76-576)

General comments

Subject category Comment text
Deposit Model Name = Placer Au (Cox and Singer, 1986; model 39a)
Deposit Other Comments = Also see the ARDF site for Yankee Creek in the Iditarod quadrangle.

Reporter information

Type Date Name Affiliation Comment
Reporter 07-AUG-01 Cameron, C.E. Northern Associates Inc.