beyond this zone, and thus its distribution partly overlaps with the late
  Harappan distributism. It is not easy to determine which began earlier,
  although one can be certain of a chronological overlap.
  A more serious problem is determining if the OCP itself is a variant of the
  late Harappan phenomenon. At sites like Ambkheri and Bargaon both
  these elements are found mixed, whereas there are other OCP sites where
  the late Harappan pottery element is absent. According to one school of
  thought the OCP complex grew out of a dispersal of early premature
  Harappans to the Doab. On the whole, there is little doubt that the late
  Harappans and the OCP complex are closely intertwined, even if we
  cannot be sure of the details.
  No other site gives a better idea of the transformation of the Harappans in
  the Doab than Hulas, a 5 ha site on the bank of the eastern Yamuna canal,
  which may represent an old drainage line. Here 43 structures of different
  phases of Harappan occupation have been excavated.
     The most significant range of evidence comes from Saipai and
Atranjikhera. Saipai has yielded sword and a harpoon from this level. At
Atranjikhera the Red-Slipped pottery was associated with the evidence of
wattle-and-daub houses supported by wooden posts. Evidence of rice, barley,
gram and cattle bones with cut marks indicates the diet of the people. Black-
and-Red Ware, copper objects, beads, wheat, rice and barley mark the next
phase at the site. This phase was followed by the iron-using, Painted Grey
Ware culture (PGW).
     Another contemporary site in the same region is Lal Qila, which is found
to possess a number of mud floor levels. Copper objects, terracotta objects,
beads, bone arrowheads and points were found here. Barley, rice and pulses
have also been found in this context.
     An important aspect of the OCP complex in this region is its association
with ‘copper hoards’. The OCP horizon and the associated finds of ‘copper
hoards’ give way in the upper Ganga valley to the Black-and-Red Ware level,
the most systematic evidence of which comes from Atranjikhera and Jakhera.
At both these sites the Black-and-Red Ware (mostly unpainted) was
accompanied by Black-Slipped