Gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

was discovered in the Yentna-Cache Creek Mining District in the U.S. state of

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

(also known separately as the Yentna District or Cache Creek District) of the upper Susitna River Valley in 1898, soon followed by claim staking.

Placer mining Placer mining () is the mining of stream bed deposits for minerals. This may be done by open-pit mining or by various surface excavating equipment or tunneling equipment. Placer mining is frequently used for precious metal deposits (particularly ...

was reported in the Cache Creek drainage of the Dutch Hills by 1906. Quaternary

glaciofluvial deposits Fluvioglacial landforms or glaciofluvial landforms are those that result from the associated erosion and deposition of sediments caused by glacial meltwater. Glaciers contain suspended sediment loads, much of which is initially picked up from the ...

, alluvial deposits, and Cenozoic conglomeratic white quartz-breccia units have been mined in the Dutch Hills. About of gold has been produced from these placer deposits.C.C. Hawley and A.L. Clark, (1973) ''Geology and Mineral Deposits of the Chulitna-Yentna Mineral Belt, Alaska'', US Geological Survey, Professional Paper 758-A. __TOC__ By 1927, a road from Talkeetna was constructed into the mining area, known today as The Petersville Road. The mining camp of Petersville, Alaska served as the area Post Office for several years in the late 1920s and early 1930s. Two areas have been set aside for recreational gold mining, the North and South units of the Petersville State Recreation Mining Areas. Many smaller one-man and family placer mining operations continue today. In addition to placer gold mining, this district in the Matanuska-Susitna borough has had some mining of

tungsten Tungsten (also called wolfram) is a chemical element; it has symbol W and atomic number 74. It is a metal found naturally on Earth almost exclusively in compounds with other elements. It was identified as a distinct element in 1781 and first ...

from

scheelite Scheelite is a calcium tungstate mineral with the chemical formula Ca W O4. It is an important ore of tungsten (wolfram). Scheelite is originally named after Swedish chemist Carl Wilhelm Scheele (1742–1786). Well-formed crystals are sought ...

deposits, and small-scale

lode In geology, a lode is a deposit of metalliferous ore that fills or is embedded in a fracture (or crack) in a rock formation or a vein of ore that is deposited or embedded between layers of rock. The current meaning (ore vein) dates from th ...

mining for gold. The district is well known due to the influence of artist Sydney Laurence and the still-unsolved murders of four miners in 1939 which gained nationwide attention (see ''The Mystery of the Cache Creek Murders'' by Roberta Sheldon). A steam-powered dragline was used to mine the placer deposits of Peters Creek, below the canyon that cuts through the Peters Hills. The tailings of that operation can be seen today, and the area is part of the Petersville State Recreation Mining Area. A cluster of deposits is in the main part of the Yentna district, near the Dutch Hills. The productive deposits here have been placer gold deposits with byproduct platinum and locally abundant

cassiterite Cassiterite is a tin oxide mineral, SnO2. It is generally opaque, but it is translucent in thin crystals. Its luster and multiple crystal faces produce a desirable gem. Cassiterite was the chief tin ore throughout ancient history and remains ...

. Gold-bearing lodes in the Yentna district, which have not been as well described, include small and locally very rich deposits associated with felsic dikes and apparently low-grade deposits in major shear and altered zones. Assays exceeding 1 ounce of gold per ton have been obtained from three of these areas, and selected quartz-arsenopyrite vein material from one prospect assayed about of gold per ton.

Cache Creek Mine

A bucketline dredge was constructed in Cache Creek in the 1920s, and used locally-abundant coal to fire the boilers. Later, a hydroelectric plant was used to run the dredge. The dredge mined the entire valley of Cache Creek as far as the mouth of Nugget Creek, then bulldozers mined what remained.

Hydraulic mining Hydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment.Paul W. Thrush, ''A Dictionary of Mining, Mineral, and Related Terms'', US Bureau of Mines, 1968, p.560. In the placer mining of ...

was also widely used before 1942, and many ditches can be found all over the Dutch Hills today. About 115,000 ounces of placer gold was reported to have been produced from Cache Creek. An active placer mine operated in 1998–1999.

The Blue Ribbon Mine

Placer Gold Mining Trommel Blue Ribbon Mine Alaska

The first reported mining in what was to become The Blue Ribbon Mine took place in 1906. Except for some stretches when no mining took place, some gold has probably been recovered every year since. The total amount recovered is unknown, but at least have been reported recovered, mostly by small-scale hand or mechanized methods. The placer mine continues operating today, and the company is actively exploring lode deposits.Dennis Garrett: ''The Blue Ribbon Mine, Alaska''

References

{{DEFAULTSORT:Yentna-Cache Creek Mining District Gold mining in Alaska Geography of Matanuska-Susitna Borough, Alaska Alaskan gold rushes Mining districts in Alaska

Cache Creek Mine

The Blue Ribbon Mine

See also

References