Divided into 'Gobi A' (Southern Altai Gobi) and 'Gobi B' (Dzungarian Gobi). Gobi A is over 4.4 million hectares in the southern part of the aimag; Gobi B is 881,000 hectares in the southwest of Gov-Altai and neighbouring Khovd. Together, the area is the fourth-largest biosphere reserve in the world and protects wild ass, Gobi bears, wild Bactrian camels and jerboas, among other endangered animals.