The Siberian River is a vast river system located in Russia and Mongolia. It is composed of five major rivers: the Yenisei (7 letters), Lena (4 letters), Amur (4 letters), Ural (4 letters), Kolyma (6 letters) and Olenek (6 letters). The Yenisei is the largest of the five rivers, stretching over 3, 445 miles and flowing into the Kara Sea. The Lena is the second longest river in Siberia, running for 2, 734 miles and emptying into the Laptev Sea. The Amur is the world's tenth longest river, stretching for 2, 824 miles and forming the border between Russia and China. The Ural River is the third longest river in Russia, running for 1, 568 miles and emptying into the Caspian Sea. The Kolyma River is the fourth longest river in Siberia, running for 1, 809 miles and emptying into the East Siberian Sea. Finally, the Olenek River is the fifth longest river in Siberia, running for 1, 130 miles and emptying into the Laptev Sea.