The rock art of Lake of the Woods (Ontario) is analyzed in an attempt to determine some basic but particular social organizational features of the society that produced it perhaps 5 000 years ago. A model for interpreting certain stylistic features of tribal art is proposed. The model is based on a consideration of the contradictory tendencies inherent in contemporary North American Indian social structure. It is argued that the interpretations generally offered in the literature fail to take account of the delicate interplay between symbols and their everyday referents, an interplay that is conditioned by the way in which aggregative and dispersive qualities in social organization are expressed in political self-expression. The model is applied to representation of turtle images, which, it is proposed, are mediators between aggregative and dispersive tendencies in Amerindian socio-political organization.