Bear Creek

Mine, Active

Commodities and mineralogy

Main commodities Au
Other commodities Ag; Cu
Ore minerals copper; gold; silver

Geographic location

Quadrangle map, 1:250,000-scale SR
Quadrangle map, 1:63,360-scale D-7
Latitude 60.9135
Longitude -149.5878
Nearby scientific data Find additional scientific data near this location
Location and accuracy Bear Creek is mainly in T. 10 N., R. 2 W., of the Seward Meridian. From its headwaters, it flows about 5 miles north into Turnagain Arm near the town of Hope. The map site of this placer mine is in the SW 1/4 section 35, T. 10 N., R. 2 W., of the Seward Meridian. This is location 139 and 140 of Cobb and Richter (1972), location 5 and 164 of MacKevett and Holloway (1977), location 10 of Cobb and Tysdal (1980), and location P-91 of Jansons and others (1984).

Geologic setting

Geologic description

Bear Creek drains an area underlain by graywacke and slate of the Valdez Group of Late Cretaceous age (Nelson, 1985). The beds strike N20E or nearly at right angles to the general course of the creek, whereas the cleavage strikes more nearly north (Martin and others, 1915). At the head of the creek there are numerous felsic dikes that trend in all directions, unlike those in other parts of the district, which generally trend north (Tuck, 1933).
The stream and bench gravels are very irregular in distribution. They consist almost entirely of the local bedrock, but also include granitic boulders. In two places, 25 to 30 feet of unstratified alluvium contains a large quantity of large, angular blocks mixed with sand and clay. Boulders 3 to 4 feet in diameter are common. In some places the surface wash is underlain by stratified sand and clay, which were probably deposited in small local basins where they in places abut against perpendicular rock faces or overlap sloping surfaces. The hard gray (so-called) glacial clay locally underlies the surface wash and rests on loose sand composed largely of slate particles. The clay contains a large amount of water (Martin and others, 1915). The lower portion of the creek flows over an alluvial fan consisting of fairly well sorted and washed gravels.
Some of the gold occurs on false bedrock. Both the creek and bench gravels are auriferous (Cobb and Tysdal, 1980). Gold is fairly coarse, yielding nuggets as heavy as 10 ounces (Jansons and others, 1984). Besides gold, native silver nuggets have been found, as well as a small amount of native copper (Moffit, 1906).
Geologic map unit (-149.589973994515, 60.9129334423045)
Mineral deposit model Placer Au (alluvial) (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Quaternary.

Production and reserves

Workings or exploration
Mining began on Bear Creek in 1894. Early mining was by pick and shovel. Hydraulic mining was done in 1904 (Moffit, 1906), but was difficult because of the presence of large boulders. These boulders were removed from the pit by derrick or cableway and were dumped along one side of the channel. This process was costly and time-consuming (Moffit, 1906).
The U.S. Bureau of Mines collected a surface sample of channel gravel in upper Bear Creek; it contained 0.0021 ounce of gold per cubic yard (Jansons and others, 1984). In 1994 or 1995, a 28-ounce nugget was recovered from the Tabatha mining claim (C. S. Huber, oral communication, 1999). Hand mining and suction dredging was still taking place in 2000.
Indication of production Yes
Reserve estimates The U.S. Bureau of Mines estimated that there is greater than 3,000,000 yards of auriferous gravels in the Bear Creek drainage (Jansons and others, 1984).
Production notes The U.S. Bureau of Mines estimated production since 1894 at 4,000 to 6,000 ounces of gold, of which less than 1,000 to 1,500 ounces have been produced since 1975 (Jansons and others, 1984).

References

MRDS Number A010624

References

Hoekzema, R.P., and Sherman, G.E., 1983, Mineral investigations in the Chugach National Forest, Alaska (Peninsula study area): U.S. Bureau of Mines in-house report; held at U.S. Bureau of Land Management Alaska State Office, Anchorage, 524 p.
Reporters Jeff A. Huber (Anchorage)
Last report date 4/17/2000