* Mountain gorillas: Found in the Virunga Mountains of Central Africa, which are shared by Rwanda, Uganda, and the Democratic Republic of Congo.
* Eastern lowland gorillas: While not strictly mountain gorillas, some populations of this species live in the Bwindi Impenetrable National Park in Uganda, a mountainous region.
Therefore, you can find mountain apes (specifically gorillas) in Rwanda, Uganda, and the Democratic Republic of Congo.