sentences:  It was not until 1999 and the Proyecto Arqueológico Teuchitlán (PAT) that Weigand began excavating Teuchitlán Culture sites, specifically the site of Los Guachimontones.However, other Teuchitlán Culture sites were excavated by other archaeologists, namely at Huitzilapa and the La Venta Corridor.Weigand noted that until relatively recently, a spring used to flow near the ceremonial center.