The Sonanadi is a paramount tributary of the Ramganga. Named after this river the Sonanadi Wildlife Sanctuary appends Jim Corbett National Park and structures an important part of the Corbett Tiger Reserve. The Sonanadi enters the Park from the northwest course and meets the Ramganga at the store.
The name Sonanadi implies river of gold. At one time grains of gold, found in the alluvial stores washed down from the higher ranges, were concentrated from the couch sand by sieving, washing and mercury treatment.