Walker Fork

Mines, Active

Commodities and mineralogy

Main commodities Au
Ore minerals gold

Geographic location

Quadrangle map, 1:250,000-scale EA
Quadrangle map, 1:63,360-scale A-1
Latitude 64.0672
Longitude -141.1045
Nearby scientific data Find additional scientific data near this location
Location and accuracy Walker Fork is a 20-mile-long tributary of the South Fork of the Fortymile River. Placer workings extend from the junction of Cherry Creek and Walker Fork,upstream to the head of the creek. There is a separate, 1-mile-long area of placer workings on Walker Fork just upstream from the confluence of Twelvemile Creek. The coordinates are the approximate midpoint of the upstream section of placer workings, in section 4, T. 26 N., R. 22 E., of the Copper River Meridian. The placer workings near Twelvemile Creek are located in section 32, T. 27 N., R. 21 E., of the Copper River Meridian. Walker Fork is localities 75 and 76 of Cobb (1972 [MF-393]), locality 63 of Eberlein and others (1977), and locality 110 of Burleigh and Lear (1994).

Geologic setting

Geologic description

The rocks along the upper Walker Fork are greenschist-facies Nasina Series carbonaceous schist and quartzite of Mississippian age (Foster, 1969 [B1271-G]; Mortensen, 1999; R.L. Flynn, unpub. data, 2000). South and west of the small town of Boundary, Walker Fork flows through metagabbro of unknown age and Paleozoic amphibolite-facies biotite gneiss and amphibolite. Most of the Walker Fork valley is broad and has extensive benches of terrace gravel as much as 400 feet above the stream (Yeend, 1996). A bench about 100 to 130 feet above the valley bottom is present along much of the north side of Walker Fork. Gold can be panned from it; 1 or 2 millimeter-size flakes per pan are common (Yeend, 1996).
The gravel in upper Walker Fork ranges from 4 to 10 feet thick and is generally covered by a thin layer of muck; in places a thin layer of clay is found between the gravel and bedrock (Mertie,1938). The pay streak is located in the bottom 2 feet of gravel and in the top foot of bedrock (Mertie, 1938); it is between 50 and 590 feet wide (Yeend, 1996). Most of the gold occurs as small flat pieces, but nuggets as heavy as an ounce were recovered. Some of the gold, particularly at the upper end of the pay streak, had a rusty or black coating (Mertie, 1938). Placer concentrates contain magnetite, limonite, ilmenite, psilomelane, pyrite, and garnet. The gold in Walker Fork is finer grained than gold on Wade Creek (Prindle, 1905). In 1936, the fineness of gold that was recovered was about 830 parts per thousand of gold, and the fineness of gold on claims upstream was about 890 parts of gold per thousand. Assays of three gold samples from Walker Fork averaged 875 parts of gold per thousand, and ranged from 830 to 904 parts of gold per thousand (Smith, 1941 [B 910-C]). Tributaries of Walker Fork with placer gold production include Davis Creek (EA155), Poker Creek (EA158), Younger Creek (EA159), Cherry Creek (EA165), and Twelvemile Creek (EA153).
Placer gold on Walker Fork was discovered in 1889, and mining began in 1903 (Mertie, 1938). The headwater tributaries of Walker Fork were mostly mined out by the turn of the century, and miners moved down to the upper part of Walker Fork (Yeend, 1996). Most of the early work on Walker Fork was done by hydraulic open-cut methods (Mertie, 1938). Annual gold production from Walker Fork and its headwater tributaries during the first few years of the 1900s was about 1,000 to 1,500 ounces (Prindle, 1905). Production from Walker Fork, Davis Creek (EA155), and Poker Creek (EA158) from 1904 to 1907 was 4,015 fine ounces of gold (Prindle, 1908 [B 345]). The Russell King dredge was installed on Walker Fork in 1907 and operated from 1907 to 1909 (Mertie, 1938). The dredge ceased mining just above Cherry Creek, probably due to the decrease in the grade of the gravels (Yeend, 1996). In 1907, the first bucket-type dredge was installed on Walker Fork about a mile above the mouth of Twelvemile Creek; it operated on Walker Fork from 1907 to 1909, and then was moved to Uhler Creek (see EA112). A second dredge, known as the Mulvane Dredge, was installed on Walker Fork between the mouths of Davis and Poker Creeks in the winter of 1907-1908 and operated until 1912, when it ceased mining a few hundred feet up Poker Creek (Mertie, 1938). Gold production from the two dredges on Walker Fork in 1909 was $130,000 (gold at $20.67 per ounce) (Ellsworth, 1910). Walker Fork Gold Corp. mined about 14 miles of claims on Walker Fork in the 1920s (Naske, 1977). From 1925 to 1934, a large steam shovel was used in hydraulic mining on Walker Fork (Mertie, 1938). From 1934 to 1938, a stacker-type dredge operated on Walker Fork; this dredge is now abandoned on Walker Fork just above the mouth of Cherry Creek (Yeend, 1996). Gravels being worked around 1936 had a value of about 45 cents to $1.05 (gold at $35 per ounce) per square yard of bedrock (Mertie, 1938).
Mining on Walker Fork occurred sporadically from 1948 into the 1990s. Bulldozers and backhoes were commonly used to move gravel to sluice boxes (Yeend, 1996). In 1955, the LaCross Mining Co. produced 965 ounces of gold and 137 ounces of silver from 20,000 cubic yards of gravel (Naske, 1977). Small open-cut operations in 1989 and the early 1990s were active in at least two locations on Walker Fork (Bundtzen and others, 1990; Yeend, 1992; Yeend, 1996). Dredge tailings were remined in the early 1990s and yielded $3.75 to $5 per cubic yard of gravel (Yeend, 1996). Small open-cut mining operations were active on Walker Fork in 2000 at several locations between Cherry Creek and Poker Creek (R.L. Flynn, unpublished data, 2000). The operation on Walker Fork near Davis Creek (EA003) has been active since 1980 (Norm LaFramboise, Boundary Explorations, Inc., written communication, 2000). Small suction dredges are occasionally seen operating on Walker Fork during the summer months near the Taylor Highway bridge (Yeend, 1996). A moderate gold resource may be present along the middle section of Walker Fork in the flood plain and terrace gravels, but mining will probably have to await more favorable market conditions (Yeend, 1996).
Geologic map unit (-141.106763166194, 64.0668914129982)
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
Placer gold on Walker Fork was discovered in 1889, and mining began in 1903 (Mertie, 1938). The headwater tributaries of Walker Fork were mostly mined out by the turn of the century, and miners moved down to the upper part of Walker Fork (Yeend, 1996). Most of the early work on Walker Fork was done by hydraulic open-cut methods (Mertie, 1938). The Russell King dredge was installed on Walker Fork in 1907 and was operated from 1907 to 1909 (Mertie, 1938). The dredge ceased mining just above Cherry Creek, probably due to the decrease in the grade of the gravels (Yeend, 1996). In 1907, the first bucket-type dredge was installed on Walker Fork about a mile above the mouth of Twelvemile Creek (see EA153); it operated on Walker Fork from 1907 to 1909, and then was moved to Uhler Creek (see EA112). A second dredge, known as the Mulvane Dredge, was installed on Walker Fork between the mouths of Davis and Poker Creeks in the winter of 1907-1908 and operated until 1912, when it ceased mining a few hundred feet up Poker Creek (Mertie, 1938). Walker Fork Gold Corp. mined about 14 miles of claims on Walker Fork in the 1920s (Naske, 1977). From 1925 to 1934, a large steam shovel was used in hydraulic mining on Walker Fork (Mertie, 1938). From 1934 to 1938, a stacker-type dredge operated on Walker Fork; this dredge is now abandoned on Walker Fork just above the mouth of Cherry Creek (Yeend, 1996).
Mining on Walker Fork occurred sporadically from 1948 into the 1990s. Bulldozers and backhoes were commonly used to move gravel to sluice boxes (Yeend, 1996). Small open-cut operations in 1989 and the early 1990s were active in at least two locations on Walker Fork (Bundtzen and others, 1990; Yeend, 1992; Yeend, 1996). Small open-cut mining operations were active on Walker Fork in 2000 at several locations between Cherry Creek and Poker Creek (R.L. Flynn, unpub. data, 2000). The operation on Walker Fork near Davis Creek (EA155) has been active since 1980 (Norm LaFramboise, Boundary Explorations, Inc., written communication, 2000). Small suction dredges are occasionally seen operating on Walker Fork during the summer months near the Taylor Highway bridge (Yeend, 1996).
Indication of production Yes; medium
Reserve estimates A moderate gold resource may be present along the middle section of Walker Fork in the flood plain and terrace gravels, but mining will probably have to await more favorable market conditions (Yeend, 1996).
Production notes Annual gold production from Walker Fork and its headwater tributaries during the first few years of the 1900s was about 1,000 to 1,500 ounces (Prindle, 1905). Production from Walker Fork, Davis Creek (EA155) and Poker Creek (EA158) from 1904 to 1907 was 4,015 fine ounces of gold (Prindle, 1908). Gold production from the two dredges on Walker Fork in 1909 was $130,000 (gold at $20.67 per ounce) (Ellsworth, 1910). Gravels being worked around 1936 had a value of about 45 cents to $1.05 (gold at $35 per ounce) per square yard of bedrock (Mertie, 1938). In 1955, the LaCross Mining Co. produced 965 ounces of gold and 137 ounces of silver from 20,000 cubic yards of gravel (Naske, 1977). Dredge tailings were remined in the early 1990s and yielded $3.75 to $5 per cubic yard of gravel (Yeend, 1996).

References

MRDS Number A015172

References

Mortensen, J.K. (compiler), 1999, Yukonage--An isotopic age database for the Yukon Territory, in Gordey, S.P., and Makepeace, A.J., compilers, Yukon Digital Geology: Indian and Northern Affairs Canada, Exploration and Geological Services Division, Yukon Region.
Naske, C.M., 1977, The historic Forty-mile District: The Northern Engineer, v. 8, no. 2, p. 38-55.
Reporters M.B. Werdon; R.L. Flynn
Last report date 5/1/2002