The Bethel district (fig. 13) includes the area drained by the Kuskokwim River below Bethel and by streams flowing into Baird Inlet, Etolin Strait, and Kuskokwim Bay as far south as, but excluding, Carter Bay. It also includes Nelson and Nunivak Islands.
Practically all of the placer mining in the district has been on tributaries of the Arolik River (fig. 14). No lode source for the gold and platinum in the placers has been found in this area, but the distribution of the deposits suggests that much of the gold may have been derived from contact zones around small granitic plutons. Altered ultramafic bodies such as one exposed along the summit of Island Mountain might have contributed the platinum-group metals. The minable placer deposits are probably the result of reconcentration of heavy minerals from glaciofluvial and glacial deposits.
Gold was discovered in the Arolik River basin in about 1900. At first only Butte Creek (4, fig. 14) was worked, but from 1913 until World War II, Kowkow Creek (3, fig. 14) and Snow Gulch (6, fig. 14) also were extensively mined. A little platinum was recovered with the gold from all these creeks. Signs of old placer activity have been reported on other creeks in the neighborhood, but the names of the miners and the results of their work are not known.
The only other place in the Bethel district where there was successful placer mining is on Rainy Creek (1, fig. 13) some gold, probably reconcentrated from glaciofiuvial or glacial depos¬its, and about 1 ton of cinnabar concentrates were recovered. The cinnabar was derived from a low-grade lode at the head of Arsenic Creek (Rutledge, 1948), a small tributary of Rainy Creek. In 1914, a little coarse gold was groundsluiced from a claim somewhere on Kapon Creek, a headwater tributary of the Eek River a few miles north of Rainy Creek (Maddren, 1915, p. 357). Associated with the gold were magnetite sand, small cinnabar pebbles, and arsenopyrite.