Surveys have revealed an average of 436 structures per square kilometer (1118 per square mile) in the site core, falling to 244 structures/km2 (626/square mile) in the periphery.Sharer & Traxler 2006, p. 686. At its height in the Late Preclassic, the population has been estimated at 1600 in the site core with a further 8000 dispersed through the periphery, to produce an estimated total population of almost ten thousand.Sharer & Traxler 2006, p. 688. In the Early Classic the population suffered a severe decline,Sharer & Traxler 2006, p. 690. population is estimated to have dropped to 34% of peak population.Sharer & Traxler 2006, p. 689. In the Late to Terminal Classic the population increased to 85% of its Late Preclassic level, an expansion that appears to have occurred rapidly and spread to all parts of the site,Sharer & Traxler 2006, p. 689. Tourtellot & González 2005, p. 73. perhaps as the result of an influx of refugees arriving from other sites around AD 830.Webster 2002, p. 278. This was followed by a population crash to 14% of peak Preclassic population in the Early Postclassic (AD 900–1200) prior to the complete abandonment of the site.Sharer & Traxler 2006, p. 689.
