The Ob River starts just south of the Russian city of Biysk in Altai Krai, and it ends when it empties into the Kara Sea. The Ob flows north and west across western Siberia, gaining sources from the Altai Mountains.
The Ob River is considered a major transportation artery through Russia and into the Arctic Sea. Its total length is 2,268 miles, with a water catchment area that is the sixth-largest in the world.
The Ob River flows through major cities in Russia, including Novosibirsk, Barnaul, Mogochin and Akademgorodok. It is Russia's fourth-longest river, and its basin contains some of the largest oil and gas drop-offs in the country.