Forthassa Gharbia is a waterhole on the High Plateaux between the Tell and Saharan Atlas ranges.

It lies slightly to the west of a line between Teniet el Sassi and the oasis of Ich, and therefore was technically within Moroccan territory, but in 1904 the boundary between Morocco and Algeria had not been delimited in this region, and there was no protest when the French occupied it.

[2] The post closed the dangerous pass of Jebel Grouz, cutting off the Beni Guil from their allies.

[5] In February 1923 Governor-General Théodore Steeg of Algeria met in Algiers with his counterparts Marshal Hubert Lyautey of Morocco and Lucien Saint of Tunisia to discuss common problems.

A joint Algerian-Moroccan police force would operate from a base at Forthassa Rharbia.