The Big Horn Medicine Wheel is one of four or five astronomically complex wheels that are publicly known to exist in the Rocky Mountain region. It is of a type termed Subgroup 6, "A prominent central stone cairn surrounded by a stone ring. Two or more interior stone lines connect the stone ring to the cairn." by John Brumley. Another of this Subgroup type is the Majorville Wheel in Alberta, Canada. The Majorville Wheel with a similar complex design matching the Big Horn Medicine Wheel has been dated archaeologically to 3200 BC. Smaller, less complex wheels may have astronomical significance, such as solstice alignments and east-west orientations. The larger complex wheels are capable of tracking several different cosmic cycles, including the precession of the equinoxes, the Moon's phases, lunar and solar eclipse cycles, and planets' orbital cycles. These astronomical wheels mirror the north ecliptic polar region of the sky and are useful as celestial grids to track changes over millennial time periods.