[2] Sensu lato, they are part of the Sarawat Mountains,[3] defining the latter as the mountain range which runs parallel to the Tihamah throughout the western portion of the Arabian Peninsula, particularly the western parts of Saudi Arabia and Yemen.

[4][5][6] The mountains consist primarily of sedimentary rock, limestone, sandstone and shale, of Jurassic, Cretaceous and Paleogene origin on a Precambrian granitic basement.

[2] The region has the highest average rainfall of Saudi Arabia[citation needed] due to largely seasonal rain.

[2] The region's crops, most of which are cultivated on steeply terraced mountainsides, include wheat, coffee, cotton, indigo, ginger, vegetables, and palms.

Several new Myxomycetes fungi species have been discovered in the region, as have a variety of previously undiscovered plants.