Medicine Wheel, WYO


     On June 21st of 2012, I visited the Medicine Wheel Mountain near the Wyoming/Montana border.

Medicine Wheel location map of the Rocky Mountain area.

     The Medicine Wheel/Medicine Mountain National Historic Landmark  is a medicine wheel located in the Bighorn National Forest, in the U.S. state of Wyoming. The Medicine Wheel at Medicine Mountain is a large stone structure made of local white limestone laid upon a bedrock of limestone. It is both a place of sacred ceremony and scientific inquiry.  It is one of many found in the Rocky Mountains of Northern America.

Ariel view of Medicine Wheel, (Image taken from a interpretive sign located at the site—public domain).

     The structure is located at an altitude of  2939 m, near the summit of Medicine Mountain. It is a pre-columbian structure, built from roughly loaf-sized stones gathered from the surrounding area. The structure consists of a circular rim, 24 m  in diameter, 28 spokes extending from the rim to the center, and a series of seven stone circles (cairns). Cairn O is at the center of the structure and is about 3 m in diameter. Cairns A – F are at or near the rim, and are considerably smaller.  The wheel has 28 spokes, the same number used in the roofs of ceremonial buildings such as the Lakota Sundance lodge. These always includes an entrance to the east, facing the rising Sun, and include 28 rafters for the 28 days in the lunar cycle. The number 28 is sacred to some of the Indian tribes because of its significance as the lunar month. In Bighorn’s case, could the special number 28 also refer to the helicial or dawn rising of Rigel 28 days past the Solstice, and Sirius another 28 past that.

The road approaching Medicine Mountain, near the Monument

     Medicine Wheel was constructed by Plains Indians between 300-800 years ago, and has been used and maintained by various groups since then.  The star alignments are most accurate for around 1200 AD, since slight changes in the Earth’s orbit have caused perturbations since. The solstice alignments remain accurate today.

Medicine Wheel of Big Horn County, Wyoming 2012

      In 1974, an archaeoastronomer named Jack Eddy visited this Medicine Wheel and studied its alignments, that is, its arrangements of rocks, cairns, and spokes. He found the arrangements point to the rising and setting places of the Sun at summer solstice, as well as the rising places of Aldebaran in Taurus, Rigel in Orion, and Sirius in Canis Major — all bright, important stars associated with the Solstice. Later another astronomer, Jack Robinson, found a cairn pair that marked the bright star Fomalhaut’s rising point with the Sun 28 days before solstice.

Image taken from an interpretive sign near the site; (Public Domain).

     Pictured above, sighting from cairn E through the center hub (which may have supported a pole) marks the summer solstice sunrise. Sighting from C through the center marked the equivalent solstice sunset.
Standing at cairn F, one could sight the once-yearly dawn, or heliacal, risings of the key stars Aldebaran, Rigel, and Sirius, which play symbolic roles in an ancient Cheyenne Massaum ceremony and are also important stars in the sacred Lakota circle constellation “The Animal”.

Looking east from Cairn F towards the rising locations of Aldebaran and Rigel 

      The dawn or heliacal rising of a star is important because it pinpoints a date exactly. This is the day a star is first seen, just before dawn, after it has been behind the Sun for an entire season. From about 1200 AD to 1700 AD, these 4 stars would have acted as solstice markers for the Native Americans – Fomalhaut (F to D) would rise 28 days before the Summer Solstice, Aldebaran (F to A) would rise during the 2 days just before the solstice, Rigel (F to B) would rise 28 days after the solstice, and Sirius (F to C) 28 days after that, at the end of August and hence marking the end of summer and time to leave the mountain.

Medicine Wheel of Big Horn County, Wyoming 2012, Looking northwest from C.

       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. 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.  It makes a good calendar for the local Shaman. 

Public domain image taken from a Cody, Wyoming museum.
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