Prior to its dissolution in 1991, the USSR was 24.4 million square miles (63 million square Km) and covered a sixth of the world’s land surface. It straddles two continents, Europe and Asia, with the Ural Mountains, running through Chelyabinsk and Perm, acting as a partition. Russia has vast natural gas supplies and many natural resources. The tundra in European Russia constitutes a quarter of the world’s forested area and the steppes, running through central Russia to Mongolia, have fertile black soil, used for agricultural production. One quarter of the pre-1991 Soviet Union was mountainous terrain, with most of the mountains (excluding the Urals and eastern Siberia) in the southern periphery in southern Siberia, Kazakhstan, Uzbekistan and Turkmenistan. Because of extensive glaciation, the Soviet Union, and the new Russian Federation, have several million inland bodies of water. This includes the largest inland body of water in the world, the Caspian Sea.