In Yukon Delta, extends along SE shore of Nunavakanuk Lake, 26 mi WSW of Mountain Village, 50 mi. S of Kwiguk Yukon-Kuskokwim Delta.
Eskimo name reported in 1867 as "Kusilvak" by Dall (1870, p. 232), U.S. Coast and Geodetic Survey (USC&GS). The plural form of the generic is relatively recent. The Russian maps called it "Ingieguk," undoubtedly the Eskimo name meaning "mountain."