Clift "et al". (2012), using dating of zircon sand grains, have shown that subsurface river channels near the Indus Valley Civilisation sites in Cholistan immediately below the dry Ghaggar-Hakra bed show sediment affinity with the Beas River in the western sites and the Sutlej and the Yamuna in the eastern ones, suggesting that the Yamuna itself, or a channel of the Yamuna, along with a channel of the Sutlej may have flowed west some time between 47,000 BCE and 10,000 BCE, well before the beginnings of Indus civilization.