Bighorn Medicine Wheel

The wheel sits just below the summit of Medicine Mountain on a spur with a long view in three directions. Its plan is simple and its execution is not: a hub cairn roughly twelve feet across, a rim some eighty feet in diameter, and twenty-eight lines of stone joining the two. Six further cairns stand on or near the rim, one of them outside it and joined to the hub by a spoke that runs past the circle. The stone is local limestone, gathered rather than quarried, and the whole structure is laid on the ground surface without excavation. The twenty-eight spokes have drawn more interpretation than anything else on the site, partly because twenty-eight is the number of poles in some Plains ceremonial lodges and the number of days in a lunar month. In 1974 the astronomer John Eddy published measurements arguing that lines between particular cairns mark the summer solstice sunrise and sunset and the heliacal risings of Aldebaran, Rigel and Sirius, with an outlying cairn and the hub forming the solstice sightline.

Later work has been more cautious: the cairns are broad, the sightlines they define are correspondingly wide, and a structure with twenty-eight radiating lines will produce coincidences. What is not in question is that the builders chose a horizon and a height, and that the people who use the site treat its orientation as meaningful.

No one knows who made the wheel or when, and the atlas records that as an open question rather than choosing among the answers. The structure offers nothing to date directly: stone laid on the surface carries no stratigraphy, and the cairns have been added to and rebuilt by users over an unknown period. Dates recovered from material at the site have returned a wide spread, and estimates in the literature run from a few centuries to several thousand years. The question of builders is harder still, because the Plains nations now associated with the site did not all occupy the Bighorn country at the same time, and the region changed hands more than once before written records begin.

Crow tradition connects the wheel to Crow history; Cheyenne, Arapaho, Shoshone and Lakota accounts connect it to theirs. These are not competing claims for an outsider to adjudicate. A site in continuous ceremonial use by several nations can be genuinely theirs in several traditions at once, and the atlas homes it at the level of Plains practice for that reason rather than assigning it to one nation and calling the others secondary. What would settle the construction date is a securely associated context, a buried feature or a datable deposit beneath an undisturbed part of the structure, excavated with tribal consent. That is an archaeological question and it has not been answered.