The Sayan intermontane steppe ecoregion (WWF ID:PA0815) is sometimes referred to as a "steppe island", being an expanse of grassland and shrubs surrounded by mountain forests in the Tyva Republic of south central Siberia, Russia. The Altai Mountains are to the west, the Sayan Mountains to the north, and the Tannu-Ola Mountains to the south. The ecoregion is in the temperate grasslands, savannas, and shrublands biome, and the Palearctic realm, with a Humid Continental climate. For much of its length, it follows the course of the upper Yenisei River. It covers 33,928 km2 (13,100 sq mi).