At the Ambo site, chips, splinters, cores, and broken or unfinished implements were spread along a terrace of the Huallaga River near the city of Ambo, Department of Huanuco, Peru. Most of the finds are obviously rejects abandoned near the source of the material from which they were made. Projectile points are abundant and were made by the percussion method, although some were retouched by the pressure method. Many of these resemble projectile points of Lauricocha II and Canario in Peru and of Ayampitin and Intihuasi in the Argentine sierra region, which are dated between 6000 and 4000 B.C.