Mountain gorillas are descendants of ancestral monkeys and apes found in Africa and Arabia during the start of the Oligocene epoch (34–24 million years ago).
The fossil record provides evidence of the hominoid primates (apes) found in east Africa about 22–32 million years ago.
There are two populations: One is found in the Virunga volcanic mountains of Central Africa, within three National Parks;
Mgahinga, in southwest Uganda; Volcanoes, in northwest Rwanda; and Virunga, in the eastern Democratic Republic of Congo (DRC).
The other population is found in Uganda's Bwindi Impenetrable National Park.