Kagamil Island lies near the NE end of the Islands of the Four Mountains archipelago in the central Aleutians, between Chuginadak and Uliaga Islands. The southern half of the 5 x 10 km island contains two undissected cones of postglacial age with small summit craters. The larger cone is located at the SE end of the NNW-SSE-trending volcano. Arcuate ridges at the northern and southern ends of the island suggest a possible earlier caldera. Hot springs and fumaroles occur along a steaming beach at the SE coast. The early explorer Veniaminof (1840) indicated that Kagamil formerly "flamed and smoked," but the only eruptive report is of unspecified activity in 1929 (Coats 1950).