Orkhon River in the context of Övörkhangai Province

The Second Turkic Khaganate was a khaganate in Central and Eastern Asia founded by Ilterish of the Ashina clan of the Göktürks and lasted from 682 to 744. It was preceded by the Eastern Turkic Khaganate (552–630) and the early Tang dynasty period (630–682). The Second Khaganate was centered on Ötüken in the upper reaches of the Orkhon River. It was succeeded by its subject Toquz Oghuz confederation, which became the Uyghur Khaganate.

The Merkit (/ˈmɜːrkɪt/; Mongolian: [ˈmircɪt]; lit. 'Wise Ones') was one of the five major tribal confederations of Mongol or Turkic origin in the 12th-century Mongolian Plateau.

The Merkits lived in the basins of the Selenga and lower Orkhon River (modern south Buryatia, Bulgan Province and Selenge Province). After a struggle of over 20 years, they were defeated in 1200 by Genghis Khan and their lands were incorporated into the Mongol Empire.

The Tuul River or Tula River (/ˈtuːl/; Mongolian: Туул гол, Tuul gol, pronounced [ˈtʰʊːɮ ɢɔɮ]; in older sources also Tola) is a river in central and northern Mongolia. Sacred to the Mongols, the Tuul is generally called the Hatan Tuul (Mongolian: Хатан Туул, [ˈχaʰtəɴ tʰʊːɮ]; lit. "Queen Tuul"). It is 882.8 kilometres or 549 miles long and drains an area of 49,840 square kilometres or 19,240 square miles. The Secret History of the Mongols (1240 AD) frequently mentions a "Black Forest of the Tuul River" where the palace of Ong Khan was located.

The river originates in the Khan Khentii Strictly Protected Area in the Khentii Mountains, in the Erdene sum of Töv aimag.From there, it travels southwest until it reaches the territory of Ulaanbaatar. Its water runs through the southern part of the capital city of Mongolia, continuing in a western direction in large loops. When it meets the border of Bulgan aimag it turns north, running along that border. After it enters Selenge aimag, it discharges into the Orkhon River near the sum center of Orkhontuul sum.

Kherlen River (also known as Kerülen; Mongolian: Хэрлэн гол; Chinese: 克鲁伦河; pinyin: Kèlǔlún hé) is a 1,254 km river in Mongolia and China. It is also one of the two longest rivers in Mongolia, along with the Orkhon River.

The Orkhon Valley Cultural Landscape sprawls along the banks of the Orkhon River in Central Mongolia, some 320 km west from the capital Ulaanbaatar. It was inscribed by UNESCO in the World Heritage List as representing the development of nomadic pastoral traditions spanning more than two millennia.

Ölziit (Mongolian: Өлзийт, Blessed) is a sum (district) of Arkhangai Province in central Mongolia. There is a concrete bridge over the Orkhon River just east of the sum center. In 2009, its population was 3,102.

Selenge (Mongolian: Сэлэнгэ) is one of the 21 aimags (provinces) of Mongolia, located in the north of the country, directly bordering Russia. It lies in the broad, fertile river basins of the Selenge and Orkhon rivers, which are among Mongolia's most important waterways. The name is derived from the Selenge river. The capital is Sükhbaatar.

The province of Darkhan-Uul, and its capital Darkhan, is an enclave inside Selenge.