Ghaggar (Drishadvati), Sarayu and some others.
    It also mentions the word samudra, which probably meant only a
collection of water and not sea in this period. The ‘Himavant’ or Himalaya
mountains were well known to the Rig Vedic sages, and one peak, that of
‘Mujavant’, is referred to as the source of soma.
  Battle of Ten Kings The Dasarajna or the battle of ten kings is an
  important historical event, and many of the important tribes and
  principalities figured in this battle. Sudas was a Bharata king of Tritsu
  family. At first, Visvamitra was the priest of Sudas, but Visvamitra was
  dismissed by Sudas who appointed Vasishtha as his priest. In revenge,
  Visvamitra led a tribal confederacy of ten kings against the Bharatas, the
  federation consisting of the five well-known tribes—Puru, Yadu, Turvasa,
  Anu and Druhyu—along with five of little note, viz. Alina, Paktha,
  Bhalanas, Siva and Vishanin. In the struggle on the Parushni (Ravi), the
  Bharatas emerged victorious. Another issue which sparked off the conflict
  was the division of the waters of the Parushni.
    There was another battle that Sudas had to fight in which the three non-
Aryan tribes—Ajas, Sigrus and Yakshus—had united under king Bheda; but
these new associations also met with the same fate with the great slaughter on
the Yamuna.
    The position and extent of the tribal settlements referred to in the Rig
Veda may be determined roughly as follows:
    1. The extreme north-west was occupied by the Gandharis, Pakthas,
        Alinas, Bhalanases and Vishanins.
    2. In upper Sind and the Punjab were settled the Sivas, Parsus, Kekayas,
        Vrichivants, Yadus, Anus, Turvasas and Druhyus.
    3. Further east (western UP) were the settlements of the Tritsus,
        Bharatas, Purus and Sirinjayas, the eastern most part being in the
        occupation of Kikatas.
    4. The Matsyas and Chedis were settled towards the south of the Punjab
        in the region of Rajasthan and Madhya Pradesh.