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 presumed Ghaggar-Hakra channel show sediment affinity not with the Ghagger-Hakra, but instead with the Beas River in the western sites and the Sutlej and the Yamuna in the eastern ones. This suggests 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. The drainage from the Yamuna may have been lost from the Ghaggar-Hakra well before the beginnings of Indus civilisation.