Mongolia’s river to the north
Most Mongolian rivers are short, seasonal or end in a lake or desert basin. The Selenge is a major exception. It is generally regarded as the country’s largest river by flow, and it carries water out of Mongolia into Russia, where it empties into Lake Baikal, the world’s deepest lake. Because the Selenge belongs to the Arctic drainage system, Mongolian water ultimately finds its way toward the Arctic Ocean by way of Baikal and the rivers beyond it. The larger setting is in the geography primer.
Figures for the river’s length and basin area depend on how the sources are counted, since the Selenge is formed by joining rivers. Treat any single number as approximate.
Where the water comes from
The Selenge is fed by many tributaries, drawing from the Khangai, Khentii and other northern ranges.
- The Orkhon is the longest river in Mongolia and a major tributary. It rises in the Khangai, passes the waterfall and valley described in the Orkhon Waterfall article, and joins the Selenge in the north.
- The Tuul rises in the Khentii region and flows past Ulaanbaatar before joining the Orkhon.
- The Eg and Ider rivers carry water from the Khangai and Khuvsgul areas. The Eg drains out of Lake Khovsgol, so the lake is part of the Baikal watershed too. The Ider and Delgermurun are among the upper rivers that form the Selenge system.
The result is a network of rivers that gathers water from a large part of northern and central Mongolia. For the mountains that feed it, see the Khangai Mountains and Khentii Mountains articles.
The link to Lake Baikal
The Selenge delta is a large wetland on the eastern shore of Lake Baikal, and the river is commonly described as the biggest single source of water flowing into the lake, often said to supply roughly half of its inflow. Because of this, what happens upstream in Mongolia can matter for the lake’s water quality. Baikal is protected as a World Heritage site, and discussions of its health often include Mongolian sections of the watershed.
This is a good example of how closely Mongolian geography is tied to its neighbors. Water, fish and pollution do not respect borders, and the two countries, along with international bodies, have cooperated on water issues. The details of agreements and projects change, so look for current sources if you want specifics.
Farmland and forests
The Selenge basin includes some of Mongolia’s best agricultural land. Along the northern valleys, there are wide plains where wheat and other crops are grown, an unusual sight in a country known for herding. The area is also home to larch and pine forest, particularly on cooler slopes, and meadows where animals graze. Farming expanded significantly during the socialist era, a period described in the article on the socialist era.
These valleys also include towns and settlements, mining areas and transport routes. The trans-Mongolian railway line crosses the area on its way between Ulaanbaatar and the Russian border, as explained in the article on the trans-Mongolian railway.
The mix of uses puts pressure on the river system. Issues often discussed include:
- Erosion and loss of riverbank vegetation due to overgrazing or tree removal
- Pollution from mining, towns and agriculture
- Changes in flow related to weather and climate
- Forest fires and logging in the upper watersheds
How serious these problems are in a given stretch of river varies, and figures differ by study. It is reasonable to say that water quality and river health are real concerns in Mongolia and the subject of ongoing monitoring and conservation efforts.
Fish and wildlife
The rivers of the Selenge system hold several fish species, including the large taimen in some stretches. Its status and fishing ethics are discussed in the article on taimen fish. The wetlands near the delta, and some in Mongolia, are important for birds. The article on birdwatching seasons covers when to look. Forests and floodplains support a range of mammals, though visitors rarely see many.
Travel along the Selenge
The Selenge region is often visited as a stop on routes between Ulaanbaatar and the north, or on trips that include Lake Khovsgol or the border region. Some points of interest include river valleys with scenic farmland, historic monasteries such as those described in Mongolian Buddhism, and areas where Mongolian and Russian influences meet. Summer is green and relatively warm, while winters are cold.
Practical notes:
- River crossings can be affected by rain and snowmelt; check road conditions locally.
- Insects can be abundant near water in summer; carry repellent.
- Do not drink untreated river water. Food and water precautions are covered in the food safety article.
- Fishing may require permits and has seasonal rules and catch-and-release customs. Check current regulations before fishing.
- Border areas have specific rules and restrictions.
A river that connects regions
The Selenge shows how a single watercourse ties together mountains, farmland, towns and an international lake. Learning to read the map by its rivers is one of the simplest ways to understand northern Mongolia, and a good counterweight to the picture of a country made only of steppe and desert.