 Llano del Jícaro was abandoned sometime after 1000 BCE and Laguna de los Cerros itself shows a significant decline at that time.The cause of this decline is not known – perhaps a shift in the course of the San Juan River – but it does roughly coincide with the decline and abandonment of San Lorenzo Tenochtitlán, which is often attributed to environmental difficulties.Laguna de los Cerros was briefly investigated by Alfonso Medellin Zenil in 1960 and by Ann Cyphers in the late 1990s and early 2000s.