Dihing or Burhi Dihing is a large tributary of the Brahmaputra in Upper Assam. The river originates in the Eastern Himalayas (the Patkai Mountain Range) in Arunachal Pradesh and flows through Tinsukia (Tinicukeeya) and Dibrugarh Districts in Assam to its confluence with the Brahmaputra at Dihingmukh. The Dihing has created number of oxbow lakes in the area. The Disam is a tributary of the Dihing in its southern bank. The Joy-Dihing Rainforest, numerous petroleum fields, wet-paddy fields, bamboo orchards and tea gardens provide a unique landscape along its course. Ledo, Margherita, Digboi, Duliajan and Naharkatia (Nahorkotiya) are the small towns in its valley.Dihing is the one of the most important contributor to the Brahmaputra river.The plains of the Dihing Valley has a rich variety of flora and fauna. The Bitel nuts are produced most in the areas of the Dihing Plains.