The Transbaikal conifer forests ecoregion (WWF ID: PA0609) covers a 1,000 km by 1,000 km region of mountainous southern taiga stretching east and south from the shores of Lake Baikal in the Southern Siberia region of Russia, and including part of northern Mongolia.

[2][3] The ecoregion is centered on the Yablonoi Mountains, a range that reaches heights of 1,600 m (5,200 ft), and runs southwest to northeast, parallel to Lake Baikal.

During the summer, the Asiatic Low brings hot air from the deserts of China and Mongolia, raising the temperature in the Transbaikal.

The characteristic trees on the warmer, wetter west side of the Yablonovsky Ridge are Dahurian larch (Larix gmelinii) and Siberian pine (Pinus sibirica).

At the lowest levels in the river valleys and lowlands (0–600 meters), the characteristic vegetation is that of the steppes: bunchgrass (Stipa capillata), fescue, junegrass (Koeleria gracilis), and Filifolium (Tanacetum sibiricum).

Unlike the Sayan and Altai mountains to the west, the climate of the Transbaikal is too extreme to support alpine meadows; the vegetation proceeds from forest directly to higher-altitude shrubs.

[5] The extensive tree cover provides good habitat for deer, bighorn sheep, bear, wild boar, and other large mammals.