Haas's early-third-millennium dates suggest that the development of coastal and inland sites occurred in parallel. But, from 2500 to 2000 BC, during the period of greatest expansion, the population and development decisively shifted toward the inland sites. All development apparently occurred at large interior sites such as Caral, though they remained dependent on fish and shellfish from the coast. The peak in dates is in keeping with Shady's dates at Caral, which show habitation from 2627 BC to 2020 BC. That coastal and inland sites developed in tandem remains disputed, however (see next section).