Dennys Gulch

Mine, Undetermined

Alternative names

O'Keefe

Commodities and mineralogy

Main commodities Au
Ore minerals gold

Geographic location

Quadrangle map, 1:250,000-scale CH
Quadrangle map, 1:63,360-scale B-5
Latitude 67.3955
Longitude -149.1413
Nearby scientific data Find additional scientific data near this location
Location and accuracy This placer mine is at an elevation of about 2,400 feet in Dennys Gulch, which is about 6 miles south of the south end of Twin Lakes. It is at the mine symbol on the 1:63,360-scale topographic map, about 0.4 mile east of the center of section 29, T. 30 N., R. 7 W.

Geologic setting

Geologic description

This record describes the placer mine in Dennys Gulch. Both this placer and the lode prospect at the head of the gulch (CH123) are associated with Denny O'Keefe, who had claims and explored the area from 1948 to 1957; much of the work on the placer and the lode probably coincided (Kurtak and others, 2002). A magnetometer survey was run over Dennys Gulch and Sawlog Creek in 1951 (Williams, 1952); there was uranium exploration by the U.S. Geological Survey in 1956 (Freeman, 1963); 6 lode claims were staked in 1955 (Heiner and Wolff, 1968); and WGM Inc. explored in the area from 1975 to 1976, and in 1983 (Dashevsky, 1986).
O'Keefe sank several shafts along the gulch, presumably at the mine shown on the 1:63,360-scale topographic map. One shaft hit bedrock at 40 feet and another at 75 feet. Only a little gold was found in these shafts, where it was concentrated in a layer of red gravel (Kurtak and others, 2002). Heiner and Wolff (1968) reported that placer gold has been mined and that coarse nuggets valued as much as $100 were recovered, but that no pay streak was found. (Kurtak and others (2002), however, imply that the coarse nuggets came from the upper part of Dennys Gulch, perhaps at or near the lode prospect there (CH123)).
Geologic map unit (-149.144030158403, 67.395093839284)
Mineral deposit model Placer Au (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Quaternary.

Production and reserves

Workings or exploration
Both this placer and the lode prospect at the head of the gulch (CH123) are associated with Denny O'Keefe, who had claims and explored the area from 1948 to 1957; much of the work on the placer and the lode probably coincided (Kurtak and others, 2002). A magnetometer survey was run over Dennys Gulch and Sawlog Creek in 1951 (Williams, 1952); there was uranium exploration by the U.S. Geological Survey in 1956 (Freeman, 1963); 6 lode claims were staked in 1955 (Heiner and Wolff, 1968); and WGM Inc. explored in the area from 1975 to 1976, and in 1983 (Dashevsky, 1986).
O'Keefe sank several shafts along the gulch, presumably at the mine shown on the 1:63,360-scale topographic map. One shaft hit bedrock at 40 feet and another at 75 feet. Only a little gold was found in these shafts where it was concentrated in a layer of red gravel (Kurtak and others, 2002). Heiner and Wolff (1968) reported that placer gold has been mined and that coarse nuggets valued as much as $100 were recovered, but that no pay streak was found. Kurtak and others (2002), however, imply that the coarse nuggets came from the upper part of Dennys Gulch, perhaps at or near the lode prospect there (CH123).
Indication of production Yes
Reserve estimates None.
Production notes Some unknown but probably small amount of gold was produced from 1948 to 1957.

Additional comments

See also Wizard (CH123) and Sawlog Creek (CH020).

References

MRDS Number A012125

References

Dashevsky, S.S., 1986, Mines, prospect, and geochemical anomalies on Doyon Ltd. regional overselection lands Alaska, Block 1 - 8, v. 1 or II: Unpublished report for Doyon Ltd., 42 p. (on file at Doyon Ltd., Fairbanks, Alaska).
Heiner, L.E., and Wolff, E.N., eds., 1968, Mineral resources of northern Alaska, Final report, submitted to the NORTH Commission: University of Alaska, Mineral Industry Research Laboratory Report No. 16, 306 p.
Kurtak, J.M., Klieforth, R.F., Clark, J.M., and Maclean, E.A., 2002, Mineral investigations in the Koyukuk mining district, northern Alaska, 2 vols.: Bureau of Land Management, Alaska Technical Report 50, 845 p.
Reporters J.M. Britton (Anchorage, Alaska); D.J. Grybeck (Contractor, U.S. Geological Survey)
Last report date 4/18/2010