The river arises in the Hindu Kush. It is formed by the confluence of the Wakhjir River and the Bozai Darya near Kashch Goz and Bozai Gumbaz, some 40 km west of the Wakhjir Pass. Shortly thereafter, the Little Pamir comes to an end, and the conjoined river contracts into a narrow, deep, rapid river, delimited by cliffs and steep hills. From here the banks have grown birch and juniper trees. 40 km west at Sarhad-e Broghil the river flows in a dramatic basin 3 km wide. Little if any vegetation but dwarf willow grows in this region.