Leninogor (lənēn´əgôr´), formerly Leninogorsk (lyĕ´nyĬnəgôrsk´), city (1989 pop. 68,706), NE Kazakhstan, in the Altai Mts. It is a mining center in an area that is the chief source of Kazakh zinc and lead. Silver, copper, and gold are also mined. The first mines were opened in the late 18th cent. Leninogor's metallurgical factories produce lead, copper, zinc concentrates, and cadmium. Until 1940 the city was known as Ridder.