Chisna River

Mine, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities Ag
Ore minerals gold
Gangue minerals magnetite

Geographic location

Quadrangle map, 1:250,000-scale MH
Quadrangle map, 1:63,360-scale A-2
Latitude 63.0727
Longitude -144.8118
Nearby scientific data Find additional scientific data near this location
Location and accuracy This mine is in the lower canyon and the flood plain of Chisna River about one-third mile below the mouth of Red Mountain Creek at an elevation of about 3,300 feet. The mine was referred to as the Lower Chesna by Mendenhall and Schrader (1903). The mine is near the historic settlement of Chisna, approximately at the north boundary of section 26, T. 21 S., R. 15 E., Fairbanks Meridian. The location is at the approximate center of a 3-mile length of the Chisna that has been mined intermittently since 1899. The Chisna mine is locality 21 on figure 6 of Cobb (1979 [OFR 79-238]), locality 70 of MacKevett and Holloway (1977), and locality 16 in table 3 of Nokleberg and others (1991).

Geologic setting

Geologic description

The Chisna River valley was occupied by ice at the height of glaciation. Surficial deposits include poorly sorted glacial moraine and somewhat sorted glacial outwash gravels of Pleistocene age and moderately sorted deposits of late Pleistocene and Holocene age on and near the modern stream (Moffit, 1944). About 1.25 miles north of the site of the old Chisna post office, the Chisna flows through a short canyon cut in felsic and intermediate volcanic rocks of the Slana Spur Formation of Pennsylvanian and Early Permian (?) age. The volcanic rocks are cut by a small diorite intrusion of probable Mesozoic age (Nokleberg and others, 1991; Moffit, 1944).
For a short distance above the mouth of the canyon, the placer deposit consisted of 4 to 8 feet of gravel with boulder deposits near bedrock. This part of the deposit was exploited by shovel-in hand operations. Below the canyon, the depth of gravel increases fairly rapidly, and the auriferous bedrock interface was not accessible to small-scale mining operations.
Placer gold at the Chisna mine is about 906 fine, or somewhat purer than gold mined upstream at Slate Creek (MH295 and MH298) and Miller Gulch (MH296); it is also finer grained and more uniform. Flakes of gold about one-eighth inch in diameter were abundant in the early mined placer deposits (Mendenhall, 1903; Mendenhall and Schrader, 1903). Most of the shallow alluvium at the mine was auriferous and had values ranging from 1.7-5.5 cents per pan to a maximum of $1.00 per pan (approximately a twentieth of an ounce) at the bedrock interface. Most of the bedrock exposed in the canyon had been swept clean of gold.
Gold was discovered in the Chisna River in the summer of 1898 (Tower, 1996), and small-scale mining commenced in 1899. By 1902, George Hazelet and A.J. Meals had a fairly extensive hydraulic operation (Mendenhall and Schrader, 1903). Attempts at mining the deeper ground below the canyon have been less successful.
Geologic map unit (-144.814021697483, 63.0722985137945)
Mineral deposit model Placer Au (Cox and Singer, 1986; model 39a).
Mineral deposit model number 39a
Age of mineralization Pleistocene and Holocene.

Production and reserves

Workings or exploration
Gold was discovered near Chisna by George Hazelet and A.J. Meals in the summer of 1898 (Tower, 1996), and mining began in the following year. An earlier discovery may have been made by Captain I.N. West in the late 1880s, but no substantial mining took place (Lethcoe and Lethcoe, 1996).
By 1902, Hazelet and Meals had constructed a ditch and mined hydraulically. By about 1910 the rich shallow deposits had been mined. Because of the remoteness of the district and resultant high costs, only the richest deposits could be mined (Moffit, 1912).
The claims downstream from a point near the canyon were surveyed and patented by Hazelet and associates. A series of unpatented claims above the canyon was part of the so-called Dempsey group or property (Moffit, 1944). These claims extend northward to the Slate Creek drainage. Some development activity was reported in this area in 1941, but there was little production.
In recent years, an attempt at large-scale open-cut mining by Del Ackels of Fairbanks was unsuccessful (Ackels, oral communication, 2001); results of modern exploration carried out for Ashton Mining Co. suggest that the remaining resource can not support a large operation (Donald Stevens, oral communication, 2001) at present gold prices (about $300 to $400 per ounce of gold). Local concentrations of high-grade gravel probably do exist.
Indication of production Yes; small
Reserve estimates A low-grade gold resource exists in the lower Chisna.
Production notes The Chisna River possibly produced a few hundred ounces of gold between 1898 and 1902 (Mendenhall and Schrader, 1903).

References

MRDS Number A011776

References

Lethcoe, Jim, and Lethcoe, Nancy, 1996, Valdez Gold Rush Trails of 1898-99: Prince William Sound Books, 136 p.
Tower, Elizabeth, 1996, Ice-bound Empire--Industry and politics on the Last Frontier, 1898-1938: Elizabeth A. Tower, Anchorage, Alaska, 302 p.
Reporters W.T. Ellis (Alaska Earth Sciences), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS)
Last report date 7/11/2003