Bettles Bar

Mine, Inactive

Alternative names

Bettles Riffle

Commodities and mineralogy

Main commodities Au
Ore minerals gold

Geographic location

Quadrangle map, 1:250,000-scale BT
Quadrangle map, 1:63,360-scale D-4
Latitude 66.9101
Longitude -151.6704
Nearby scientific data Find additional scientific data near this location
Location and accuracy Bettles Bar is on the east bank of the Koyukuk River, opposite the old site of Bettles, and about 0.5 mile downstream from the junction of John and Koyukuk Rivers. The mine is in NE1/4 of section 16, T. 24 N., R. 19 W., of the Fairbanks Meridian. The location is accurate within one-half mile.

Geologic setting

Geologic description

The gold in the Bettles Bar deposit is in a gravel layer composed of rounded cobbles embedded in fine sand, which in turn is mostly covered by a layer of fine river sand and silt (Reed, 1938). The gold is immediately below the sand and silt in the upper three feet of the cobble-and-sand layer, and is distributed throughout the sand fraction. The gold is very fine; so fine that when dry it is said to float. Although the locations of the bar deposits are relatively fixed, the individual spots where the river concentrates the gold are said to change from year to year (Reed, 1938). The deposits can be as much as 15 feet above the low-water level of the river (Reed, 1938). Similar deposits also occur along the Koyukuk River in the Bettles area, particularly at the so-called the Bettles Riffle near the Bettles Airport, at Evansville (Kurtak and others, 2002).
According to Reed (1938), with some effort, a person could generally recover as much as $10 per day (gold at $35 per ounce) working these bar deposits. In 1937, as much as $600 in gold was said to have been recovered in two weeks by a man working a short distance above Bettles. Grybeck (1977) indicated mining activity through 1975.
Bettles Bar is one of a number of gold placers in the gravel bars along the Koyukuk River from Bettles upstream to the vicinity of Tramway Bar (Reed, 1938). See also Tramway Bar (WI006), Hanshaw Bar (WI005), and Grubstake Bar (WI004) in the Wiseman quadrangle.
Geologic map unit (-151.673095766472, 66.9096338403199)
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 Surface mining. Grybeck (1977) indicated mining activity through 1975.
Indication of production Yes; small
Production notes According to Reed (1938), with some effort, a person could generally recover as much as $10 per day (gold at $35 per ounce) working these bar deposits. In 1937, as much as $600 in gold was said to have been recovered in two weeks by a man working a short distance above Bettles.

References