Sheep Creek

Mine, Inactive

Alternative names

Sheep Gulch

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-6
Latitude 67.4965
Longitude -149.8061
Nearby scientific data Find additional scientific data near this location
Location and accuracy Sheep Creek is a west-flowing tributary to the Middle Fork Koyukuk River. The mine is shown by symbol and label on the 1:63,360-scale topographic map. It is about 0.5 mile west of the center of section 21, T. 31 N., R. 10 W. Placer mining extends for about 0.5 mile downstream and 1 mile upstream from the mine symbol on the map.

Geologic setting

Geologic description

There are several generations of mining on Sheep Creek and much old mining equipment remains on the property (Kurtak and others, 2002). Tailings piles up to 30 feet high are along the creek from 1,500 feet to 2,100 feet elevation. The first production was in 1907, and by 1914, 113 ounces of gold had been produced Maddren, 1913). The creek was mined most years between 1933 and 1942, both by drift mining and by booming and shoveling, along the modern stream channel; 543 ounces of gold was produced. There was mining in 1948 and 1949, and in 2000, Bureau of Land Management geologists found evidence of recent mining.
Reed (1938) reported that the Sheep Creek placers are in both the modern channel and a deep channel. In 1910, the deep channel was discovered along the north side of the creek and mined for about 7,000 feet upstream, beginning where the valley of Sheep Creek opens into the valley of the Middle Fork Koyukuk River. Above this, the deep channel grades into the modern stream stream channel. At the lower end of the deep channel, the gravel was about 90 feet thick and was drift mined. There are few large boulders in the tailings from the deep channel. The gravel from the deep channel ran about $1 per square foot of bedrock in 1937, but some small areas had much more gold. The deep channel could extend west into the relatively flat valley of the Middle Fork Koyukuk River, but it may have been cut off as was the deep channel of Gold Creek (CH080) about a mile to the north.
Reed (1938) implied that mining had then just begun in the modern channel of Sheep Creek, about 1,000 feet upstream from where Sheep Creek valley enters the valley of the Middle Fork. The gravel over the schist bedrock was about 6 feet thick and very coarse with many large schist boulders. The gold was coarse and water worn. The preliminary estimates in 1937 were that the ground had about $0.50 in gold (0.014 ounces) per square foot of bedrock.
Kurtak and others (2002) panned samples along the creek and many contained visible gold. However, they indicated that there is probably little unmined gravel left along the creek.
Geologic map unit (-149.80884825204, 67.4960833101962)
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 There are several generations of mining on Sheep Creek and much old mining equipment remains on the property (Kurtak and others, 2002). Tailings piles up to 30 feet high are along the creek from 1,500 feet to 2,100 feet elevation. The first production was in 1907, and by 1914, 113 ounces of gold had bee produced (Maddren, 1913). The creek was mined most years between 1933 and 1942, both by drift mining and by booming and shoveling along the modern stream channel. There was mining in 1948 and 1949, and in 2000, Bureau of Land Management geologists found evidence of recent mining.
Indication of production Yes; small
Reserve estimates Kurtak and others (2002) indicated that there was probably little unmined gravel left along the creek.
Production notes Kurtak and others (2002) document that 780 ounces of gold was produced from 1907 to 1948 but the records are incomplete. Most of the gold was produced from 1907 to 1914 and from 1933 to 1942. There may have been mining as recently as 2000.

Additional comments

MAS No. 0020310044

References

MRDS Number A011032

References

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