|Quadrangle map, 1:250,000-scale||WI|
|Quadrangle map, 1:63,360-scale||B-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Hammond River is a large, northern tributary of the Middle Fork, Koyukuk River. The mouth of the Hammond River is about 4 miles northeast of Wiseman and 3 miles east of Midnight Dome. The productive part of the river begins about 1.5 miles above its mouth near the mouth of Jennie Creek (WI169) and extends upriver for about 3 miles to the mouth of Vermont Creek (WI027). For this record, the coordinates are about 0.5 mile south of the center of section 19, T. 31 N., R. 11 W., near the midpoint of the productive section.|
The Hammond River is one of the largest gold producers in the Koyukuk District. Most of the production has come from a three-mile section of the river that extends from the mouth of Jennie Creek (WI169) to the mouth of Vermont Creek (WI027).
Gold was discovered on the Hammond River about 1900 about 2 miles above its mouth (Maddren, 1913). Early work concentrated on mining the shallow gravel along the modern stream channel, notably near the discovery claim about 0.4 mile upstream from the mouth of Jennie Creek and along river meanders as far upstream as Buckeye Gulch (WI100). According to Maddren (1913), mining in the modern channel produced about $8,000 to $10,000 in gold (gold at $20.67 per ounce) by 1913. Most of these deposits were soon mined out although some shallow ground was mined as recently as from 1985 to 1987 near the mouth of Swift Creek and probably elsewhere over the years.
In 1911, drift mining began on the deep channel below the Hammond River and it is the major source of the gold. The deep channel has been mined from near the mouth of Buckeye Gulch to about a mile and a half above the mouth of the river. The lower end of the deep channel extends into the valley of the Middle Fork, Koyukuk River, but is truncated there, presumably by glacial scouring. The deep channel was about 114 feet deep about 0.2 mile above the mouth of Jennie Creek and was thought to be too deep and wet to mine downstream. The deep channel, except for a few areas overlooked by the early miners, was thought to be mined out by 1937 (Reed, 1938). Workings in one of these overlooked areas in 1936 and 1937 found a section 8-10 thick of paying gravel. The channel was 35 feet wide and the depth to bedrock was 115 feet. The gravel consisted of small boulders and large cobbles, separated by sand and fine gravel. The gravel was frozen to bedrock (although this was not always the case at other locations along the deep channel) and the bedrock was described as hard schist (Reed, 1938). The gravel of the deep channel was said to become richer downstream. The gold in the deep channel is on bedrock; it is coarse, rounded, and waterworn. Galena and pyrite locally accompany the gold. Much coarse gold has been produced from the Hammond River. Several 40- and 50-ounce nuggets were found, and one weighed 137 ounces (Maddren, 1913; Dillon, 1982). Mosier and Lewis (1986) reported that gold in 14 samples from Hammond River varied from from 845 to 929 fine with a median fineness of 900. According to Reed (1938), the ground was valued at about $1.46 per square foot of bedrock (gold at $35 per ounce). At that time, little gold had been found in the deep channel above the mouth of Buckeye Gulch. However, from 1991 to 1995, there was an attempt to mine the deep channel between Buckeye Gulch and Vermont Creek with earth moving equipment. That attempt was unsuccessful due to flooding and silting of the workings.
Gold also occurs in sections of a high channel preserved along the lower Hammond River. These sections appear to be 40-50 feet above the modern river bed and were first encountered where the high channel is cut by tributary streams such as at Buckeye Gulch (WI100). (There are also much higher bench placers that are described separately, notably the Slisco Bench (WI031) southwest of the mouth of Vermont Creek.). In the late 1990s several mines worked these benches between Gold Bottom Gulch and Jennie Creek, but getting water to them was difficult.An examination in 2011 (by D.J. Grybeck) of the satellite imagery available widely on the internet shows evidence of extensive modern surface placer mining with earth moving equipment at several sites along the Hammond River: 1) opposite the mouth of Jennie Creek; 2) about 2,000 to 3,000 feet upstream; 3) on the opposite side of the river and just upstream from the mouth of Steep Creek; 4) near the mouth of Swift Creek (WI102) , and 5) near the mouth of Buckeye Gulch (WI100).
|Geologic map unit||(-150.095449713101, 67.4899765709537)|
|Mineral deposit model||Placer Au (Cox and Singer, 1986; model 39a).|
|Mineral deposit model number||39a|
|Age of mineralization||Quaternary.|
|Workings or exploration||From 1900 to at least 2001, there have been numerous mines in operation along the Hammond River from the mouth of Jennie Creek to the mouth of Vermont Creek (Kurtak and others, 2002). Early mining concentrated on shallow ground along the modern stream channel but this ground was soon exhausted. In 1911, drift mining began on a deep channel that extended from the mouth of Buckeye Gulch to the mouth of Jennie Creek and most of the gold mined from the Hammond River has come from this deep channel. The deep channel was thought to be mined out by 1938 but various mining operations have continued to mine into the 21st century on remnants of shallow ground and benches along the river, using earth moving equipment and suction dredges. An examination in 2011 (by D.J. Grybeck) of the satellite imagery available widely on the internet shows evidence of extensive modern surface placer mining with earth moving equipment at several sites along the Hammond River: 1) opposite the mouth of Jennie Creek; 2) about 2,000 to 3,000 feet upstream; 3) on the opposite side of the river and just upstream from the mouth of Steep Creek; 4) near the mouth of Swift Creek (WI102); and 5) near the mouth of Buckeye Gulch (WI100).|
|Indication of production||Yes; small|
|Reserve estimates||Probably no substantial reserves remain but there may be remnant pockets of unmined auriferous gravel.|
|Production notes||The total placer gold production from the Hammond River is uncertain, but it has been large. Bliss and others (1988) indicate that total production may be more than 31,746 ounces and as much as 47,620 ounces (but this includes the substantial production from the tributary streams to the Hammond River). Eden (2000) reported that 17,256 ounces of gold was produced from the Hammond River between 1904 and 1999. Kurtak and others (2002) give yearly production figures from 1900 to 1943 that total 19,128 ounces of gold, but they note that the production records are incomplete. The peak of the production was from 1913 to 1916 when 15,705 ounces of gold was mined and most of that probably came from drift mining on the deep channel.|
Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Chandalar and Wiseman quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-340, 205 p.
Dillon, J.T., 1982, Source of lode and placer gold deposits of the Chandalar and upper Koyukuk Districts: Alaska Division of Geological and Geophysical Surveys Open-File Report AOF-158, 25 p., 1 sheet, scale 1:250,000.
Eden, K., 2000, Geology and gold mineralization of the Nolan area in the Brooks Range, Alaska: U.S. Bureau of Land Management Open-File Report 78, 87 p.
Kurtak, J.M., Klieforth, R.F., Clark, J.M., and Maclean, E.A., 2002, Mineral investigations in the Koyukuk mining district, northern Alaska: Final Report: U.S. Bureau of Land Management Technical Report 50, v. 1 and 2, 845 p.
Kurtak, J.M., Klieforth, R.F., Clark, J.M., and Williams, E.M., 1999, Mineral investigations in the Koyukuk mining district, northern Alaska--Progress Report: U.S. Bureau of Land Management Open-File Report 74, 158 p.
Maddren, A.G., 1910, The Koyukuk-Chandalar gold region: U.S. Geological Survey Bulletin 442-G, p. 284-315.
Maddren, A.G., 1913, The Koyukuk-Chandalar region, Alaska: U.S. Geological Survey Bulletin 532, 119 p.
Mosier, E.L., and Lewis, J.S., 1986, Analytical results, geochemical signatures, and sample locality map of lode gold, placer gold, and heavy-mineral concentrates from the Koyukuk-Chandalar mining district, Alaska: U.S. Geological Survey Open-File Report 86-345, 172 p.
Mulligan, J.J., 1974, Mineral resources of the Trans-Alaska Pipeline corridor: U.S. Bureau of Mines Information Circular 8626, 24 p., 9 sheets, scale 1:250,000.
Reed, I.M., 1938, Upper Koyukuk region, Alaska: Alaska Territorial Department of Mines Miscellaneous Report 194-7, 169 p.
|Reporters||J.M. Britton (Anchorage); D.J. Grybeck (Contractor, USGS)|
|Last report date||2/1/2011|