Medicine wheels, or sacred hoops, were constructed by laying stones in a particular pattern on the ground. Most medicine wheels follow the basic pattern of having a center of stone(s), and surrounding that is an outer ring of stones with "spokes", or lines of rocks radiating from the center. Some ancient types of sacred architecture were built by laying stones on the surface of the ground in particular patterns common to aboriginal peoples.
Originally, and still today, medicine wheels are stone structures constructed by certain indigenous peoples of North America for various astronomical, ritual, healing, and teaching purposes. Medicine wheels are still 'opened' or inaugurated in Native American spirituality where they are more often referred to as "sacred hoops", which is the favored English rendering by some. There are various native words to describe the ancient forms and types of rock alignments. One teaching involves the description of the four directions.
More recently, syncretic, hybridized uses of medicine wheels, magic circles, and mandala sacred technology are employed in New Age, Wiccan, Pagan and other spiritual discourse throughout the World. The rite of the sacred hoop and medicine wheel differed and differs amongst indigenous traditions, as it now does between non-indigenous peoples, and between traditional and modernist variations. The essential nature of the rite common to these divergent traditions deserves further anthropological exploration as does an exegesis of their valence.
Medicine wheels look like a wagon wheel laying on its side. Some reach diameters of 75 feet. Although archeologists aren't exactly sure what each one was used for, it is thought that they probably had ceremonial or astronomical significance.
Erecting massive stone structures is a well-documented activity of ancient man, from the Egyptian pyramids to Stonehenge, and the natives of Northern America are no different in this regard. What does separate them from the rest is how non-intrusive their structures were. Unlike the usual towering stone monoliths, the natives simply laid down lots of stones on the earth in certain arrangements. One of the more obtuse arrangements is the medicine wheel.
Medicine wheels appear all over northern United States and southern Canada, specifically South Dakota, Wyoming, Montana, Alberta, and Saskatchewan. Most of the wheels have been found in Alberta. In all over 70 medicine wheels have been found.
One of the prototypical medicine wheels is in Big Horn County, Wyoming. This 75 foot diameter wheel has 28 spokes, and is part of a vast set of old Native American sites that document 7,000 years of their history in that area. It is located on a ridge of Medicine Mountain, part of northern Wyoming's Big Horn Range.
It is a circular arrangement of stones measuring 75 feet across with 28 rows of stones that radiate from a central cairn to an encircling stone rim. Placed around the periphery of the wheel are five smaller, stone circles. The Medicine Wheel's function and builders remain a mystery. However, there is general agreement that it was built approximately 200 years ago by indigenous Native Americans, and that its 28 "spokes" may symbolize the days in a lunar month. To Native Americans, this remains a sacred, ceremonial site.
Medicine wheels were constructed by laying stones in a particular pattern on the ground. Most medicine wheels follow the basic pattern of having a center cairn of stones, and surrounding that would be an outer ring of stones, then there would be "spokes", or lines of rocks, coming out the cairn.
Almost all medicine wheels would have at least two of the three elements mentioned above (the center cairn, the outer ring, and the spokes), but beyond that there were many variations on this basic design, and every wheel found has been unique and has had its own style and eccentricities.
The most common deviation between different wheels are the spokes. There is no set number of spokes for a medicine wheel to have. The spokes within each wheel are rarely evenly spaced out, or even all the same length. Some medicine wheels will have one particular spoke that's significantly longer than the rest, suggesting something important about the direction it points.
Another variation is whether the spokes start from the center cairn and go out only to the outer ring, or whether they go past the outer ring, or whether they start at the outer ring and go out from there.
An odd variation sometimes found in medicine wheels is the presence of a passageway, or a doorway, in the circles. The outer ring of stones will be broken, and there will be a stone path leading up to the center of the wheel.
Also many medicine wheels have various other circles around the outside of the wheel, sometimes attached to spokes or the outer ring, and sometimes just seemingly floating free of the main structure.
What do they mean?
Medicine wheels have been built and used for so long, and each one has enough unique characteristics, that archeologists have found it nearly impossible to tell exactly what each one was for, and haven't had much success at making broad generalizations about their function and meaning.
One of the older wheels has been dated to over 4,500 years old; it had been built up by successive generations who would add new features to the circle. Due to the long existence of such a basic structure, archeologists suspect that the function and meaning of the medicine wheel changed over time, and it is doubtful that we will ever know what the original purpose was.
It is not hard to imagine that medicine wheels, like most large stone structures, would probably have served a ceremonial or ritual purpose. There is evidence of dancing within some of the wheels. Other wheels were probably used as part of a ritual vision quest.
Astronomer John Eddy put forth the theory that some of the wheels had astronomical significance, where the longest spoke on a wheel could be pointing to a certain star at a certain time of the year, suggesting that the wheels were a way to mark certain days of the year.
Other scientists have shown that some of the wheels mark the longest day of the year. (Note that an astronomical/calendar theory has been suggested for just about every unnatural stone structure on Earth.)