Arrow Grotto, an inner sanctum deep within a mountain of south-central New Mexico and reached only by a crawlway from Feather Cave, was found to contain masses of offerings untouched for six centuries or more. Examination of material and of accompanying pictographs by men from several living pueblos led to identification of the grotto as a shrine for Earth Mother and Sun Father, visited at the period of biannual solar ceremonies. Parallels between Arrow Grotto, other prehistoric ceremonial caves, and even the Anasazi sipapu, show a pattern surprisingly similar to that of a number of Pueblo ceremonial caves in use today or in the recent past. Parallels to concepts regarding caves and supernaturals in Mexican cultures indicate a series of rapid northward diffusions of religious ideas, the first, at least, from eastern Mesoamerica, through Preclassic to Postclassic periods, one of our most specific evidences of influential contacts.
Original owners of Feather Cave and Arrow Grotto probably were Piros who left the Rio Bonito Valley to become mingled, eventually, with southern Tiwa relatives, whose descendants still inhabit pueblos near Albuquerque.