The Selenge River is the longest river in Mongolia, stretching approximately 1,124 kilometers (698 miles). It originates from the Khangai Mountains and flows northward into Lake Baikal in Russia, making it a significant waterway in the region. The river plays a crucial role in the local ecosystem and supports various wildlife. The Selenge River basin is vital for agriculture and fishing, providing resources for communities along its banks. It is also an important source of water for both domestic and industrial use. The river's health is essential for maintaining the biodiversity of the surrounding areas.