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.