This is the largest river in the east of Gilan with a watershed covering an area of 1,725 sq. km. The 'Chak Rood' is one of the biggest branches flowing through the western areas of 'Kalishan' and 'Moosa Kalayeh', opposite Rostam Abad along the course of the Sefid Rood. Its other tributary is 'Gol Rood'which takes its source in Ashkoorat.