Khar Us Nuur National Park: Mapped Geography and Protected Wetland Landscapes in Khovd Province

Khar Us Nuur National Park was formally established in 1997 as part of Mongolia's broader effort to protect representative landscapes and ecosystems outside the country's better-known northern and eastern reserves. The lakes it protects had long held regional significance for wildlife, particularly as breeding habitat for waterbirds, but their conservation status was formalized only in the late twentieth century.

Geologically, the present-day lakes are remnants of a much larger single body of water that existed in the region roughly 5,000 years ago. As that lake shrank and fragmented under a drying climate, the current chain of Khar-Us Nuur, Khar Lake, and Dörgön Lake emerged as the principal surviving waterbodies in the Great Lakes Basin of western Mongolia.

In the 1960s, muskrat were introduced to the lakes and marshes for fur production. The population has since grown considerably, and the species now exerts ongoing pressure on the reed beds that are central to the park's birdlife and ecological character, adding a long-running management challenge to the park's history.

The landscape of Khar Us Nuur National Park is defined by the alternation between open water and dry land. Three large lakes form the core of the protected area, with Khar-Us Nuur as the dominant feature. At about 1,850 square kilometers in extent and stretching around 70 kilometers at its longest axis, it is the largest of the three lakes by a wide margin. The freshwater character of Khar-Us is maintained by the Khovd River, which enters the lake through a well-developed delta on the western shore.

Within Khar-Us Nuur, the island of Agbash covers roughly 274 square kilometers, providing an unusual enclosed habitat of steppe and lakeshore within the lake itself. Immediately east of Khar-Us sits Khar Lake, a smaller freshwater body covering around 565 square kilometers. Beyond it, connected by a canal, lies Dörgön Lake, a saline waterbody of about 300 square kilometers, marking a clear shift in water chemistry along the chain.

The southern edge of the lake basin rises to Mount Jargalant, a prominent Altai peak reaching approximately 3,800 meters in elevation. Beyond the lakes and their bordering marshes, the surrounding terrain is predominantly semi-arid desert steppe, characteristic of the Great Lakes Basin. The result is a landscape where high mountains, broad freshwater and saline lakes, interior islands, and arid grasslands coexist within a single protected unit.

The ecosystems of Khar Us Nuur National Park reflect the meeting of water and steppe in the Great Lakes Basin. The dominant habitat type is open lake and wetland, with extensive reed marshes along the shorelines of Khar-Us Nuur and Khar Lake shaping much of the ecological character. These marshes are dominated by Phragmites, the tall common reed that forms dense beds across the lake margins.

Beyond the wetlands, the protected area incorporates large tracts of semi-arid desert steppe. Vegetation in these areas is shaped by limited precipitation, averaging around 120 millimeters per year, and by long winters when the lakes freeze over for roughly half the year. At higher elevations, the slopes of Mount Jargalant and the surrounding Altai foothills add upland habitats that contrast with both the wetlands and the open steppe.

The mix of freshwater lakes, saline lake, marshland, island steppe, and mountain slopes supports a notable concentration of biodiversity. Although the climate is cold and dry, the presence of persistent open water and extensive reed habitat allows the wetland zones to function as regional biodiversity hotspots within an otherwise arid landscape.

The wildlife significance of Khar Us Nuur National Park is closely tied to its lakes and marshes. More than 200 bird species have been recorded in the park, making it one of the most important wetland bird areas in western Mongolia and a regional stronghold for waterbirds that depend on large reed-bed systems.

Among the notable species are globally threatened and near-threatened waterbirds. The endangered white-headed duck occurs here, while the near-threatened Dalmatian pelican was once a regular breeder in the park, though in more recent years it has been recorded primarily as a passage visitor. The vulnerable swan goose is also among the species for which the park's marshes hold conservation importance.

The lakes additionally support distinctive fish life, including three endemic species such as the narrow-headed Altai osman. A non-native addition to the fauna is the muskrat, introduced in the 1960s for fur production. The muskrat population has expanded substantially and now places significant pressure on the reed beds, an interaction that has become an important feature of the park's modern wildlife management challenges.

Khar Us Nuur National Park is classified as an IUCN Category II protected area, recognizing it as a national park of national-level importance. Its conservation significance is rooted in the international importance of its wetland habitats, particularly the reed marshes that ring the lakes and support a rich community of breeding and migratory waterbirds.

The park is situated within the Great Lakes Basin desert steppe ecoregion and plays a key role in protecting representative landscapes of this part of western Mongolia. By maintaining a connected system of freshwater and saline lakes surrounded by intact steppe and Altai mountain slopes, the park helps conserve the ecological contrasts that define the region.

A persistent conservation challenge concerns the introduced muskrat population. Originally brought into the area for fur production in the 1960s, muskrats have become well established and now affect the very reed beds that support the park's internationally important birdlife. Managing this interaction between invasive species and sensitive wetland habitat remains a central element of the park's conservation agenda.

Khar Us Nuur National Park's strongest points of distinction are its three large interconnected lakes and the surrounding reed marshes that host over 200 bird species. The presence of globally threatened species such as the white-headed duck, Dalmatian pelican, and swan goose gives the park clear international conservation relevance.

Equally notable is the geographic setting. Within a single protected area, visitors encounter freshwater and saline lakes, the large interior island of Agbash, the bordering semi-arid steppe of the Great Lakes Basin, and the high slopes of the Altai Mountains, including Mount Jargalant on the southern shore of Khar-Us Nuur.

The park experiences a cold semi-arid climate, with winters long enough for the lakes to remain frozen from roughly November through April. As a result, late spring through autumn is the most natural window for experiencing the lakes in open water and for observing the breeding and staging waterbirds that depend on the reed marshes.

Summer brings milder temperatures and the most active wildlife behavior around the wetlands, while the shoulder seasons of late spring and early autumn offer quieter conditions and marked changes in light across the lake basins. Winter visits would mean the lakes are frozen and wildlife activity is reduced, and therefore are less suitable for typical park experiences centered on water and birdlife.