“If in the nineteenth century most scholars identified the Ghaggar-Hakra's course with the Vedic Sarasvati, it is basically for three reasons. The Rig-Veda, the oldest of the four Vedas, mentions various rivers but praises the Sarasvati above all others: it was a "mighty river" flowing "from the mountain to the sea", and one hymn listed it between the Yamuna and the Sutlej - precisely the location of the Ghaggar-Hakra. Secondly, the local traditions regarding the "lost river" of the Indian desert matched those in the post-Vedic literature (including the Mahabharata), which recorded the gradual disappearance of the Sarasvati. Thirdly, scholars noticed a minor tributary of the Ghaggar called "Sarsuti", an obvious corruption of "Sarasvati": it rises in the Sirmur hills that are part of the Shivaliks and was marked on British maps as early as in 1788. Putting these three lines of evidence together, they concluded that the lost Sarasvati could only have flowed in the Ghaggar's bed.”

Supporting the claim that Ghaggar-Hakra is the Sarasvati river, as quoted in " Sarasvati: Tracing the death of a river http://www.dnaindia.com/blogs/post-sarasvati-tracing-the-death-of-a-river-1581502" DNA India (12 June 2010)