From south to north the Endicott Mountains present long, broad glaciated valleys with rounded hills between rising in the center of the range to steep tors and aretes.

The northern slopes of the Endicotts are steeper and more heavily incised, before they give way to the Arctic Coastal Plain.

Above the crystalline basement PreCambrian and Paleozoic sediments that have undergone partial metamorphosis .

[2][3][4][5][6][7] The Kanayuk Conglomerate is a fluvial deposit, made by a river in its flood plain, and can be up to 8,000 feet (2,400 m) thick.

[7] The Kanayuk Conglomerate began to be deposited in the Devonian and continued through into the Mississippian (early Carboniferous).