Bööntsagaan

Bööntsagaan lies in Mongolia’s Valley of the Lakes, a long intermontane depression between the Khangai and Govi-Altai mountains. The valley stretches some five hundred kilometers and is about one hundred kilometers wide, mostly between one thousand and fourteen hundred meters above sea level. Sandy and rocky plains dominate the floor, with solonchak and takir soils around shallow saline lakes. Böön Tsagaan is one of the two largest lakes in this chain, together with Orog, and has a broad, saucer-like basin. Rivers rising in the Khangai Mountains feed the lakes, while no permanent inflow arrives from the Gobi-Altai side. Because the water supply depends on these mountain streams, lake levels fluctuate strongly with the seasons and between years; some basins can dry completely. As the lakes shrink in summer, they expose salt marsh, particularly east of Böön Tsagaan. Barchan dunes line the valley margins, and the nearby Govi-Altai zone is seismically active. The shallow lakes provide important staging grounds for migratory waterfowl and habitat for fish endemic to western Mongolia, giving this austere landscape seasonal ecological importance.