Atrek River

The Atrek River (Persian:, Turkmen: Etrek derasy) is a fast-flowing river that originates in the highlands of north-eastern Iran (37°10′N 59°00′E) and travels 563 kilometers (350 miles) westward until discharging into the south-eastern corner of the Caspian Sea in Turkmenistan.

It only flows into the Caspian when it is in flood level due to the intensive usage of its waters for agriculture. The river defines the boundary between Iran and Turkmenistan, beginning around 37°59′28′′N 55°16′29′′E, when its tributary the Sumbar joins it; this helped keep the area closed during the Cold War years.

The Atrek River is a 669-kilometer (416-mile) river that drains a 27,300-square-kilometer basin (10,500 sq mi). Despite the fact that sturgeons congregate along the Turkmen shore in the Caspian Sea, they do not now migrate into the Atrek River due to its low water level and pollution. Sturgeons no longer spawn in Turkmenistan because the Atrek is the sole Caspian watershed river on the Turkmen coast. This river is one of the longest rivers in Turkmenistan.

Length: 563 km