About 1,183,662 hectares (2,924,893 acres; 11,837 km2; 4,570 sq mi) in size, the park occupies the entirety of the Tunkinsky District of the Republic of Buryatia.

The park is found at a meeting point of taiga, steppe, alpine forest and lake ecosystems.

[6] As a bio-diverse and isolated park, Tunkinsky is home to a wide variety of animals: over 305 vertebrates have been identified, of which 62 have been characterized as rare or endangered.

[8] These are transitional zone forests, containing species from both the Siberian Taiga and the Mongolian Steppe, primarily pine, cedar and larch.

The small spa resort town of Arshan lies at the base of the Sayan Mountains, and is known for its carbonate mineral springs.