Why were the Medicine Wheels Built and For What were They Used?

There are hundreds of known medicine wheels in North America with the majority of them in Canada. Although they are numerous, only a small percentage have been studied. In that small percentage, an interesting correspondence has been discovered: most of these wheels have a cairn, or central pile of stones, that can be used to align to the sunrise at summer solstice. Could this be a coincidence, or an important step in unraveling their mysteries?

The more elaborate constructs of the Bighorn and Moose Mountain medicine wheels have become the center of the studies of astronomers and archaeologists alike. What makes these two wheels so unique is that they are thought to be aligned to other objects in the sky as well as the summer solstice Sun.

Jack Eddy Medicine Wheel Alignments

Solar and Stellar Alignments

Astronomer John Eddy* became intrigued by the cairns of the Bighorn medicine wheel in the 1970s. He discovered that one pair of cairns was aligned to solstice sunrise and another to solstice sunset. But he could find no answer for the existence of the other cairns. They seemed to have a purpose since they were so prominent. What could it be?

Dr. Eddy began his search with the sunrises and sunsets of other important dates, such as winter solstice and the equinoxs but found no correlations. Not easily deterred, he checked for alignments to the Moon and stars. The paths and cycles of the Moon lead to nothing substantial. However, in the stars he found an intriguing correlation. Because of the Bighorn wheel's location, on top of a high and windy mountain, the wheel is only accessible for about two months in mid summer. The rest of the year the wind-swept plateau is covered in snow and freezing cold. Eddy needed a starting point so he began looking for stars that were in the sky in the months before and after summer solstice, when the mountain was accessible.

What he found were alignments to three stars during their heliacal risings. Heliacal risings occur when a star has been behind the Sun for a season, but is just returning to visibility. There is one morning when the star "blinks" on before the sunrise. That one special morning is called the star's heliacal rising. Not all stars have heliacal risings because some stars remain above the horizon all the time. Only certain stars rise and flash into existence in the predawn glow of the horizon. Each day that passes after the heliacal rising, the star will appear to rise earlier and remain in the sky longer until its soft glow is obliterated by the rising sun. Because these helical risings were so specific, just one day, they were used by many different ancient civilizations to mark specific events such as the drought season and planting time. It is not surprising that the Plains Indians would use heliacal risings to signal the coming and going of the solstice.

Eddy found that three major cairn-pairs had corresponding heliciacal rising alignments to Aldeberan, Rigel, and Sirius, three of the brightest stars in the sky. A later researcher found a cairn alignment for Fomalhaut, another very bright star. These alignments all occur from standing and sighting at one specific cairn.

Bighorn Medicine Wheel
The heliacal rising of Aldeberan signals the coming of the summer solstice in just a couple days. Rigel rises almost exactly one lunar month (28 days) after Aldeberan and Sirius one month after Rigel. This could account for for Bighorn's 28 spokes. The rising of Sirius could be the signal to pack up and leave Bighorn because the weather was going to take a severe turn. The alignment of Fomalhaut occurs 28 days before the solstice.

For more details on the astronomical alignments, see Petroform Astronomy.

What else might the wheels have been used for?

There are many different ideas about the origins of the wheels and the reasons they were built. One of the most exciting connections to the wheels is the Plains Indian Sun Dance. For many of the Plains Indians, the Sun Dance was their major communal religious ceremony. Generally held in the late spring or early summer, the rite celebrates renewal, spiritual rebirth, and regeneration of the living Earth with all its components. The ritual involves staring at the Sun while dancing, sacrifice, and supplication to insure harmony between all living things. Contemporary Native Americans continue this practice today.

Some researchers believe that Bighorn closely resembles a Medicine Lodge or Sun Lodge. These structures were built out of wood by the Plains Indians for the their sacred Sun Dance ceremony. This supposition is supported by the lack of timber in the area where Bighorn was built. Stone would have been a more abundant building materials. wood. However, this correspondence does not fit with all medicine wheels since Bighorn is one of the few wheels that resemble the shape of the lodge.

The heliacal alignments on the Bighorn wheel could be as simply as signifing the times of year when the weather is suitable for being on the mountain. The rising of Sirius would hav been the signal to pack up and leave before the winter weather set in.

We do know that wheels had many different uses and those uses changed over the years from tribe to tribe. Some of them were used as burial mounds, or created to mark a special day in history. Some of them point not only to the Sun but other medicine wheels or natural resources. There seems to be evidence that some of the wheels were updated over the centuries to track the slight changes in solar and stellar alignments.


* Eddy, John A, "Astronomical Alignments of the Bighorn Medicine Wheel," Science 184(4141):1035-1043; 1974.

Image credits:

  • Medicine Wheel sunset photograph by Tom Melham. The Tom Melham photograph appeared in the National Geographic. According to them, it is part of a collection "Mysteries of Mankind: Earth's Unexplained Landmarks" and the image is listed as usuable, with no permission or payment required. One does need to give credit, which is: Medicine Wheel sunset photograph by Tom Melham.
  • Medicine Wheel color photo by Richard Collier, Wyoming State Historic Preservation Office. Used with permission.
  • Diagram from original by Jack Eddy
  • Alignment diagram copyright (c) 2002 Moncur Gallery, the research conducted at the Boissevain Community Archives and Morton Regional Library by James Ritchie. Used with permission.

©2005 by Stanford SOLAR Center | Permitted Uses | Credits