Shatudru is the ancient name of Sutlej River and it is mentioned in the Hindu scriptures. There is an interesting story as to how Shatudru River got its name.
Legend has it that a man-eating Rakshasa entered the body of King Saudasa. He then roamed around forest eating human beings. One day he devoured all the 100 sons of Sage Vasishta.
Unable to bear the loss of his sons, the sage attempted to kill himself. But all his attempts failed.
He then threw himself into Sutlej River which was infested with crocodiles. The Sage hoped that the crocodiles would kill him.
But the River divided itself into hundred rivers and followed in hundred directions to save the Sage.
As the river divided itself into hundred it came to be known as Shatudru.