The Zangmar (also known as the Ṭłmut River) is a river in Maku County, West Azarbaijan Province, Iran. It originates in the Zagros Mountains above Maku, Iran along the Iran–Turkey border, not far from Mount Ararat and flows south and east into the Araxes at the town of Pol Dasht. A major tributary of the Zangmar is the Barun River which is dammed at 39.18806°N, 44.48194°W some 12 mi above Maku, forming the Maku-Barun reservoir. The dam is rammed earth and riprap with a clay lining 78 m high, impounding some 135000000 m3 of water. Beyond Maku, the Zangmar flows past Tappeh Bashi-ye Namaz, and Moradluy-e Olya before entering the Araxes.