The Sivalik Hills, also known as Churia Hills, are a mountain range of the outer Himalayas that stretches from the Indus River about 2,400 km (1,500 mi) eastwards close to the Brahmaputra River. It is 10–50 km (6.2–31.1 mi) wide with an average altitude of 1,500–2,000 m (4,900–6,600 ft)