The northern slopes of the Alai chain are richer in trees.
At its south-western extremity the Kokshal-tau merges in the Kokiya Mountains (16,000-18,000 ft.), which at their other end are met by the Alai Mountains and the Terek-tau.
The border-ridges of the Alai Mountains, the Khantengri group, the Sailughem range and the West Sayan contain the highest peaks of their respective regions.
In the Alai region there are other extensive glaciers, e.g.
The Hissar range, a westward continuation of the Alai Mountains, separates the Zarafshan from the tributaries of the Oxus - the Surkhan, Kafirnihan and Vakhsh.
The Alai is a well-defined ridge with steep slopes, and both it and the Terek-tau, which prolongs it towards the Kokshal-tau, are flanked next the Ferghana valley by what appear to be the old uplifted strata both of the old Palaeozoic series of metamorphic limestones and of the newer Tertiary series of softer conglomerates and sandstones.
Kashgar has connexion with Ferghana and Bokhara over the Kyzyl-art pass (14,015 ft.) and down the Alai valley.
Max Friedrichsen) assign both the Alai and the Trans-Alai Mountains to the Pamirs.
The other arm of the bifurcation, situated farther south, and beginning at the Terek-tau, is double; it consists of the Alai and Trans-Alai ranges, continued westwards in the Karateghin, Zarafshan, Hissar and Turkestan ranges, though orographically the Trans-Alai ought probably to be described as the border-ridge of the Pamir plateau.
The administration of kazas, or cantons, was usually entrusted to the cadis and the holders of the more important fiefs; the sanjaks, or departments, were ruled by alai beys or mir-i-livas (colonels or brigadiers), pashas with one horsetail; the vilayets, or provinces, by beylerbeys or mir-i-mirans (lord of lords), pashas with two horse-tails; these were all originally military officers, who, in addition to their administrative functions, were charged with the duty of mustering and commanding the feudal levies in war time.