It is possible to track mountain gorillas in Uganda, Rwanda and Congo every day and every year.  In Uganda: Bwindi Impenetrable National Park, in Rwanda: Volcanoes National Park and in Congo: Virunga National Park. The number of available habituated Mountain Gorilla groups or families for tourist to track varies through the year depending on the location of the Mountain Gorilla family groups. Gorilla groups often travel into the Congo or beyond the range of a day trek to visit them. Sometimes Mountain Gorilla family groups travel rapidly, break up and reform, or show behaviors that make them less attractive to visit. Other habituated Mountain Gorilla groups are dedicated to research and not open to tourist tracking.