This study documents consensus and variation in the interpretation of symbolism in Navajo sandpaintings of the heavens. Navajo sandpaintings are sacred designs created to attract supernaturals and to create a ritual reality in which the patient and supernaturals interact for the purpose of curing and blessing. Precise rules of tradition determine the form of all images. Yet even ritual forms are created by individuals whose unique experiences pattern their interpretation of forms. Thus, ritual images index a system of cultural knowledge which possesses the interpretive variability and consensus of belief characteristic of any system of cultural knowledge. This study focuses on celestial constellations because they are a universally perceivable domain which therefore facilitates cross-cultural and intracultural comparison. This study identifies those constellations which are salient for the Navajo and documents their visual depiction in sandpaintings. By examining a corpus of sandpaintings defined by subject matter--sandpaintings with constellations--across ceremonials (sandpainting not limited to one chantway), more detailed comparison of form and meaning becomes possible. Thus, such variation can be systematically documented. Several factors are at work to produce this variation: the nature of the oral transmission process, infrequent performance of sandpaintings which contain constellations, and the relatively monotonous nature of constellation images in comparison to other more distinctive features in the sandpaintings. Interpretive variability in meaning is related to chantway specialization: different chanters provide different interpretations of the same constellation depending upon their ceremonial specialization. A fundamental internal consistency exists in the use of the same cognitive principles applied by chanters to identify and order the constellations and in the way they project key symbols from their chant specializations onto the constellations. Because constellations do not play a dominant role in chantway stories (which form the basis for sandpaintings)--relative to other supernaturals--variation in their depiction and interpretation is not disruptive of the ceremonial-symbolic system.