The film "Gorillas in the Mist" is based on the true story of Dian Fossey, an American primatologist and conservationist who dedicated her life to studying and protecting mountain gorillas in Africa. The movie is adapted from Fossey's autobiography of the same name and also draws from articles by Harold T. P. Hayes and Alex Shoumatoff. It portrays Fossey's pioneering research with mountain gorillas in Rwanda, her fight against poaching, and her efforts to conserve these endangered animals until her murder in 1985.