Apex complex is a cultural tradition of the Middle Archaic period. Apex complex artifacts, dated from about 3000 to 500 BC, first appeared in the Magic Mountain site near Apex Creek in Colorado. The Irwins, archaeologists at Magic Mountain, believe that the artifacts are from ancestors of Puebloan people of the American southwest. The cultural complex is distinguished by its Apex projectile points, which were noted for the increase in their frequency as one starts from the bottom to the top zone of the Magic Mountain site. Discovered tools also included scrapers, choppers, and leaf-shaped bifaces, which may have been used as knives.