heads at 590600N1610000W flows SW to Hagemeister Strait at Estus Point, 27 mi. SE of Platinum, Kilbuck-Kuskokwim Mts.
Eskimo name reported in 1849 by Captain Tebenkov (1852, map4), Imperial Russian Navy (IRN), as "R(eka) Azvichvyak." In 1880 Ivan Petroff (1884) reported the name of the Eskimo village at its mouth as "Aziavik." According to Frank Waskey, local trader and prospector, "Uzavigiak" is a variation. The local name Osviak River, reported in 1947 by U.S. Geological Survey (USGS), was derived from this name.