Tramway Bar Mine, Koyukuk Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Tramway Bar Mine	Mine
Koyukuk Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: Tramway Bar is located on the west side of the Middle Fork, Koyukuk River, about 0.4 mile south-southwest of Chapman Island; Tramway Bar is labeled on the Wiseman A-1 topographic map. The placer deposit is located on a bench about 80 to 100 feet above river level. The location is accurate.
Geology: The Tramway Bar mine is one of the first placer gold occurrences known in the area; it was discovered as early as 1885. The gravel that contains the gold is presumed to have been deposited by streams flowing in the Middle Fork Koyukuk River valley prior to downcutting of the Middle Fork canyon. The deposit at Tramway Bar consists of about 4-7 feet of coarse, waterworn, bouldery gravel. It lays on a bench cut in conglomerate and sandstone, along the west side of the Middle Fork canyon wall about 50 - 100 feet above the modern river channel. These gravels were mined across a 50 foot width for about a mile. One mining operation, active in 1937 described by Reed (1938), recovered both coarse, worn, and rounded gold, and very fine, flaky gold. The coarse gold occurs throughout a 3-5 foot section of coarse gravel, but mostly in the lower part. The fine gold occurs mostly in a layer on top of decomposed conglomerate bedrock. No large nuggets accompanied the coarse gold. The early miners were said to have recovered only the coarse gold. Maddren (1913) suggested that the gold at Tramway Bar was derived from the outwash of Chapman Creek. Reed (1938) thought that the coarse gold might have been reconcentrated from outwash material in the Middle Fork valley, and that the fine gold was derived from erosion of the conglomerate bedrock. Maddren reported production of about $8,000 in gold (approximately 400 ounces) between 1900 and 1909. Gold values in 1937 were said to be about $0.31 per square foot of bedrock (Reed, 1938). Mining continued sporadically at least until 1965 (Cobb, 1973).
Workings: The placer was mined by hand methods such as rocking and shoveling into sluice boxes.
Age: Quaternary.
Production: Maddren reported production of about $8,000 (approximately 425 oz.) between 1900 and 1909. Gold values in 1937 were said to be about $0.31 per square foot of bedrock (Reed, 1938). Mining continued sporadically at least until 1965 (Cobb, 1973).

Commodities (Major) - Au
Development Status: Yes
Deposit Model: Placer Au (Cox and Singer, 1986; model 39a)

Other Databases

Link to USGS - Alaska:	WI156

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References