A volcano and a lake together
Khorgo-Terkhiin Tsagaan Lake National Park lies in Arkhangai province in central Mongolia, in the northern part of the Khangai highlands. It protects two features that belong together: an extinct volcano called Khorgo and a large freshwater lake, Terkhiin Tsagaan Nuur, whose name is usually translated as “White Lake of the Terkh.”
The area is a good reminder that Mongolia’s landscape is not only steppe and desert. Volcanic activity, river systems and mountain building have all left their mark here, which links well with the wider picture of the Khangai Mountains and their hot springs.
How the lake was formed
The commonly given explanation is that lava flows from volcanic activity in the area blocked a valley and dammed the Suman River, and the water that collected behind this natural barrier formed the lake. The Terkh River also feeds it, and water leaves through an outlet river that continues onward. The volcanic eruptions are generally dated to some thousands of years ago, but scientific sources give differing estimates, so it is safest to say simply that they are geologically recent rather than ancient.
Because the lake sits at a fairly high elevation and is fed by mountain streams, the water is cold and fresh. Its size makes it large enough that the far shore can look hazy on a calm day, and in some seasons it freezes over.
The Khorgo crater
Khorgo is a low volcanic cone with a wide crater at the top. A path leads up from a base area, and the walk to the rim is short but can be steep and breezy. From the rim you can look across the crater, which has a cover of grass and shrubs, and out over fields of dark, broken lava that spread across the valley below. In places, vegetation grows in cracks in the rock.
Local people treat the volcano as a special place. Sacred cairns, known as ovoo, often mark the summit area, and visitors sometimes walk around them clockwise and add a stone. If you do the same, do it respectfully and quietly. The rock is rough and uneven, so wear sturdy shoes and take care with children.
The lava fields themselves include odd cracks, small caves and vents. Stay on the paths, because the ground can be unstable and sharp, and it is easy to twist an ankle.
Wildlife and habitats
The mix of lake, wetland, forest edge and open hillside supports a variety of life. Waterbirds are a highlight, including ducks, geese and gulls that stop at the lake during migration, and the best months for birdwatching are usually spring and fall. Fish live in the lake, and local rules about fishing may apply. Forested slopes nearby shelter animals such as deer, and marmots can often be seen in sunny meadows. As always, sightings are never guaranteed.
Local life
Herder families graze animals around the lake in summer, and you may see gers beside the shoreline or among the larches. Some families host guests, and ger camps are available nearby in the busy season. The usual visiting etiquette applies, and it is worth reviewing the guidance on visiting a herder family and on respectful photography.
Getting there and timing
The park is far from Ulaanbaatar by Mongolian standards, and the journey normally takes much of a day or longer by road, depending on the route and the condition of the roads. Many travelers combine it with other places in central Mongolia, for example waterfall and valley destinations along the Orkhon route, which is described in the article on Orkhon Waterfall. Road quality changes over time and with the weather, so ask recently returned travelers or drivers.
Summer is the standard season, with mild days and chilly nights. Winter brings severe cold and a frozen lake, and many camps close. Pack layers and rain gear, and carry insect repellent for the damp areas near water.
Looking after the area
The lake and lava fields are fragile in different ways. Keep to marked paths, do not remove rocks or plants, avoid washing with soap in the lake, and take all rubbish with you. Fires should only be made where permitted. If you walk or camp near the shore, keep a respectful distance from nesting birds and grazing livestock. Fees may be charged at the park entrance, and current details should be confirmed with official sources.