The range is named after a confederation of nomadic and semi-nomadic tribes, all of which claim to hail from Arab ancestors of Banu Hilal origin.

The range is formed by mountains created by folds of the early Tertiary which remained relatively undisturbed after formation but have been heavily eroded.

They only grow in the few places at the feet of the Ouled Naïl mountains that are at an altitude below 600 m, such as near Bou Saada and the Oued Djedi.

[2] Two important towns are located in the immediate area of the range, Bou-Saada to the north at the feet of the mountains and Djelfa in the middle of the range at an elevation of 1,208 m. North of Djelfa town there is an imposing physical feature known as Rocher de Sel (English: Salt Rock) that was formed from the erosion of rock salts and marls by rain.

Djelfa is an important market centre for the Ouled Naïl who live in black-and-red striped tents and claim ancient Arab descent.