The range serves as a weather system barrier in Morocco running east–west and separating the Sahara from the Mediterranean and continental zones to the north and west.

Here, the contrasting landscapes are similar to Colorado in the United States, with high plateaux, gorges and box canyons, and peaks sometimes splintered by erosion.

This portion of the range includes the solid mass of the Tamlelt whose northern edge is occupied by its higher peaks, such Jbel Ayachi at 3,747 m (12,293 ft).

This massif became an internationally famous paleontological site after the discovery of the bones of a dinosaur called 'Atlasaurus',[3] which populated Morocco 180 million years ago.

[citation needed] The Atlas Mountains define an ENE-WSW trending intracontinental belt, resulting from the tectonic inversion of the Late Triassic to Middle Jurassic rift basin during the Cenozoic convergence between the African and Eurasian Plates.

[4] During the Triassic, the central High Atlas extensional basin was characterized by the synrift deposition of red beds and localized evaporites capped by extensive basaltic lava flows.

The Jurassic Atlas basin was open to the east (western Tethys realm) with Paleozoic provenance areas located toward the west and south.

[5] Normal faulting and block tilting increased notably during Pliensbachian times, resulting in north to south compartmentalization of the basin.

[5] Global anoxia during the latest Pliensbachian and the earliest Toarcian occurred in close association with regional drowning of the lower Liassic platforms and localized deposition of basinal marls.

This mixed system progressively graded to an extensive shallow water carbonate platform of the Anoual Formation, Bajocian to early Bathonian in age that is recognized throughout the central High Atlas.

[5] Finally, the middle Dogger to Lower Cretaceous red beds record the sedimentation of continental to shallow marine transitional deposits that characterize the central High Atlas domain.

Fully marine environmental conditions and platform carbonate deposits, which locally crop out in the margins of the Atlas System, dominated between Aptian and Cenomanian times.

[7] At the foot of the High Atlas one finds Aït Benhaddou, a ksar (Maghribi Arabic: قـصـر, romanized: qṣer, fortified village) still in use.