Geologists have long identified ‘a wide dry channel coming south from the spot near Ropar where the Satluj abruptly swings westward’; that palaeochannel meets the Ghaggar near Shatrana, some 60 km south of Patiala, close to the point where the Sarsuti also joins the Ghaggar. It roughly follows the bed of the seasonal Patialewali. Remarkably, notes Valdiya, ‘at the point of confluence, the Ghaggar channel suddenly becomes 6-8 km wide—and remains unusually wide until it loses itself in the sand dunes of the Thar desert, west of Anupgarh’. This sudden broadening of the Ghaggar is the unmistakable sign that it once received some of the Sutlej’s waters at this point.