Atrek

The Atrek (also Atrak and Etrek) (Persian: اترک, Turkmen: Etrek derýasy) is a fast-moving river which begins in the mountains of Northeastern Iran (37°10′N 59°00′E / 37.167°N 59°E / 37.167; 59), and flows 563 km (350 mi) westward draining into the southeastern corner of the Caspian Sea in Turkmenistan. Because of the high use of its waters for irrigation, it only flows into the Caspian when it is in flood stage. The Atrek is 669 km long and drains a basin of 27 300 km². Beginning at 37°59′28″N 55°16′29″E / 37.99111°N 55.27472°E / 37.99111; 55.27472, where its tributary the Sumbar join it, the river forms the border of Iran with Turkmenistan; this helped keep the area closed throughout the Cold War years. A 1926 treaty between Iran...