The Biri River rises in the south of the Western Bahr el Ghazal near the border with Haut-Mbomou in the Central African Republic.

It flows in a north-northeast direction past Deim Zubeir (which lies to the east), then northeast to the border with Northern Bahr el Ghazal, where it joins the Chel or Kuru River from the left.

[1] The first European to visit the river appears to have been Dr. Georg August Schweinfurth, who spent three years exploring the Bahr-el-Ghazal region before returning to Europe in the fall of 1871.

He did not take any astronomical observation, so did not record latitude or longitude, but did keep an excellent dead reckoning of distances and direction.

[3] In June 1894 a Belgian force under Xavier-Ernest Donckier de Donceel entered the region from the southwest.