The Indus is one of the few rivers in the world to exhibit a tidal bore. The Indus system is largely fed by the snows and glaciers of the Himalayas, Karakoram and the Hindu Kush ranges of Tibet, the Indian states and union territories of Ladakh and Himachal Pradesh and the Gilgit-Baltistan region of Pakistan. The flow of the river is also determined by the seasons - it diminishes greatly in the winter, while flooding its banks in the monsoon months from July to September. There is also evidence of a steady shift in the course of the river since prehistoric times - it deviated westwards from flowing into the Rann of Kutch and adjoining Banni grasslands after the 1816 earthquake. Presently, Indus water flows in to the Rann of Kutch during its floods breaching flood banks.