Mongolia occupies 1,564,116 square kilometers in East Asia between Russia to the north and China to the south. The country contains no coastline and sits landlocked at an average elevation of 1,580 meters above sea level. The territory extends roughly 2,392 kilometers from east to west and 1,259 kilometers from north to south. Mongolia ranks as the 18th largest country by area and the most sparsely populated sovereign nation, with approximately 3.3 million people distributed across this expanse. The Mongolian Plateau forms the dominant geographical structure, a vast elevated region characterized by limited drainage to external seas. Most of Mongolia's water systems flow internally or terminate in closed basins rather than reaching oceans.
The Gobi Desert occupies the southern third of Mongolia, covering approximately 500,000 square kilometers of Mongolian territory as part of a larger desert system extending into China. The Gobi consists primarily of bare rock and compacted gravel rather than sand dunes, though localized sand formations exist in areas like Khongoryn Els where dunes reach heights of 300 meters. Annual precipitation in the Gobi averages 50 to 100 millimeters, concentrated in brief summer periods. Temperatures in the Gobi range from minus 40 degrees Celsius in winter to 45 degrees Celsius in summer, creating one of the most extreme temperature ranges on Earth. The desert elevation sits between 900 and 1,500 meters. Gobi Gurvansaikhan National Park protects 27,000 square kilometers of desert landscape in the South Gobi Province, established in 1993 to preserve the ecosystem that includes wild Bactrian camels, snow leopards, and argali sheep.
The Altai Mountains form Mongolia's western boundary with China and Russia, running northwest to southeast for approximately 1,000 kilometers through Mongolian territory. Tavan Bogd, meaning "five saints," comprises the highest peaks in the range, with Khüiten Peak reaching 4,374 meters as Mongolia's highest point. The Altai system contains over 200 glaciers, though measurements from 2010 to 2020 show retreat rates averaging 0.5 to 1.5 percent annually. The mountains formed through tectonic collision between the Siberian and Kazakh plates during the Paleozoic era, with continued tectonic activity producing measurable earthquakes. Altai Tavan Bogd National Park covers 6,362 square kilometers in Bayan-Ölgii Province, established in 1996. The Altai region receives 200 to 400 millimeters of precipitation annually, substantially more than surrounding areas, creating conditions for alpine meadows and forests that contrast with desert and steppe ecosystems elsewhere in Mongolia.
The Khangai Mountains occupy central Mongolia in a northwest-southeast arc spanning approximately 800 kilometers. The range reaches maximum elevation at Otgontenger Peak, measuring 4,021 meters in Zavkhan Province. The Khangai system formed through volcanic activity during the Cenozoic era, with basalt formations and crater lakes providing evidence of geological history. The mountains create a climatic division in Mongolia, blocking moisture-bearing winds from the northwest and contributing to the aridity of the Gobi to the south. The Khangai region contains the headwaters of Mongolia's major river systems including the Orkhon, Selenge, and numerous tributaries. Forests of Siberian larch and pine cover northern slopes where annual precipitation reaches 300 to 500 millimeters. The Orkhon Valley, designated a UNESCO World Heritage site in 2004, sits within the Khangai foothills and contains archaeological evidence of nomadic cultures dating to the Bronze Age, including Karakorum, the 13th-century capital of the Mongol Empire established by Ögedei Khan in 1235.
The Khentii Mountains extend northeast from Ulaanbaatar toward the Russian border, covering approximately 80,000 square kilometers. Asralt Khairkhan rises to 2,800 meters as the range's highest point. Khan Khentii Strictly Protected Area encompasses 12,270 square kilometers, established in 1992 and expanded in 1998, protecting boreal forest and alpine ecosystems. The Khentii holds significance in Mongolian culture as the probable birthplace of Genghis Khan, though precise locations remain unconfirmed through archaeological evidence. The mountains form part of the watershed between the Arctic Ocean and Pacific Ocean basins. The Onon River, one of two rivers forming the Amur, originates in the Khentii and flows northeast into Russia. Annual precipitation in the Khentii ranges from 250 millimeters in southern sections to 500 millimeters in northern valleys, supporting extensive taiga forests of larch, pine, and birch.
Lake Khövsgöl sits in northern Mongolia at 1,645 meters elevation, measuring 136 kilometers long, 36 kilometers wide at maximum width, and reaching depths of 262 meters. The lake contains approximately 380 cubic kilometers of water, representing 70 percent of Mongolia's fresh water and 0.4 percent of global fresh water reserves. Khövsgöl formed through tectonic activity along the same fault system that created Lake Baikal, located 195 kilometers to the northeast in Russia. The Selenge River system drains Khövsgöl through the Egiin Gol tributary. The lake freezes from January through May with ice thickness reaching 1 to 1.5 meters, sufficient to support vehicles during winter months. Khövsgöl Nuur National Park surrounds the lake, established in 1992 and expanded to 8,381 square kilometers in 1997. Water temperature reaches 10 to 14 degrees Celsius in summer surface layers. The lake contains 9 fish species and 1,000 documented plant species in the watershed. Tsaatan communities, numbering approximately 200 to 400 individuals, practice reindeer herding in the mountains east of Khövsgöl.
Lake Uvs occupies the western extreme of Mongolia in Uvs Province at 759 meters elevation, making it the lowest point in Mongolia. The lake measures 84 kilometers long and 79 kilometers wide with a surface area of 3,350 square kilometers, though dimensions fluctuate substantially based on precipitation and evaporation. Maximum depth reaches 20 meters in the northeastern section. Uvs has no outlet, creating saline conditions with salt concentration of 18.7 grams per liter, approximately half the salinity of ocean water. The lake freezes solid from October through May. Uvs Nuur Basin received UNESCO World Heritage designation in 2003 as a transboundary site shared with Russia, protecting 10,688 square kilometers in Mongolia. The basin contains desert, steppe, forest, and tundra ecosystems within a compact geographical area. Summer temperatures at lake level reach 35 degrees Celsius while winter temperatures drop to minus 45 degrees Celsius. The basin serves as critical habitat for migratory waterfowl with documented populations exceeding 2 million birds during spring and autumn migrations.
The Selenge River originates in Mongolia's Khangai Mountains and flows 992 kilometers north through Mongolia before entering Russia and Lake Baikal. The river drains approximately 447,000 square kilometers, including 283,000 square kilometers in Mongolia representing 18 percent of the country's territory. Major tributaries include the Orkhon, Kharaa, Yeroo, and Delger rivers. The Selenge carries annual flow volume of approximately 11 cubic kilometers measured at the Russian border. Peak flows occur from May through July following snowmelt and early summer rains. The Orkhon River, the Selenge's largest tributary, extends 1,124 kilometers from headwaters in the Khangai Mountains. Orkhon flow volume averages 4.5 cubic kilometers annually. The Orkhon Valley Cultural Landscape, inscribed as a UNESCO World Heritage site in 2004, protects 121,967 hectares along the river containing archaeological sites from Paleolithic through Mongol Empire periods.