The Yenisei, or Yenisey, River begins in the Hangayn Mountains of Central Mongolia. The river ends in the Kara Sea at the Arctic Ocean. The Renisei River is 3,534 miles long, making it the fifth longest river on Earth.
The start of the Yenisei River is with the merging of the rivers Kaa-Khem and Bii-Khem. It then flows through the countries of Mongolia and Russia before opening into the Arctic Ocean. Most of the Yenisei remains frozen for a large portion of the year. Within the river's watershed lies Lake Baikai, which is the largest freshwater lake in the world, based on volume. The river provides a source of hydroelectric power near its mouth at the Kara Sea.