Dian Fossey (/daɪˈæn ˈfɒsi/; January 16, 1932 – c. December 26, 1985) was an American zoologist who undertook an extensive study of gorilla groups over a period of 18 years. She studied them daily in the mountain forests of Rwanda, initially encouraged to work there by anthropologist Louis Leakey. Her 1983 book, Gorillas in the Mist, combines her scientific study of the mountain gorilla at Karisoke Research Center with her own personal story. It was adapted into a 1988 film. Fossey was murdered in 1985; the case remains open.