The Eg-Uur watershed area (EUWA) is located in a remote region of northern Mongolia and is home to one of the world's most robust Taimen populations. The Eg River, 474 km in length with a 40,454 km2 catchment area, originates from Lake Hovsgol and flows south where it meets with the Uur River. The Uur river, 331 km in length with 12,300 km2 of catchment area and originates from the Kheven-Saluu mountains in northeastern Hovsgol Province flowing south until it meets the Eg river. The combined Eg-Uur, recognized from this point on as the Eg River, flows for another 200 km until it reaches the Selenge River, a tributary of Lake Baikal.

The triangular-shaped watershed area, consisting of the Eg and Uur rivers to the point of confluence with the Selenge River, is recognized as the Eg-Uur Watershed Area (EUWA), a total area of approximately 3.48 million ha, which constitutes about 16.3 percent of the total catchment of the Arctic Basin in Mongolia. The EUWA covers territories of 6 districts in Hovsgol province (Alag-Erdene, Hatgal, Tunel, Chandmani-Undur, Tsagaan-Uur and Erdenebulgan), and one district in Bulgan province (Teshig).