Religious Practices of the Diegueño Indians, by T.T. Waterman, [1910], at sacred-texts.com
We may, in conclusion, carry away several definite facts concerning the religion of the Diegueño people. One such fact is, that a certain part of their religious practices are, so far as externals are concerned, common also to the Luiseño and Cahuilla. An equally rich and much older part of this worship is thoroughly and inherently Diegueño. As a basis for at least this older part of their ceremonial, they have a rich and varied, though not a voluminous mythology. We are entitled to a vehement suspicion that the songs invariably used as the accompaniment of their dances, bear a definite reference to this mythology. In fact only the somewhat advanced decadence of their religious practices, and the unfortunate fact that their language has never been exhaustively studied, prevent the final establishment of this fact. In this one trait alone they somewhat resemble their kindred, the Mohave. In mythology, finally, they offer a sharp contrast to their Shoshonean neighbors, the Luiseño and Cahuilla. The real affiliation of the Diegueño religion is, like that of their mythology, probably to be sought among their kindred, the other southwest peoples of Yuman stock.