Astronomer John Eddy investigated the Big Horn Medicine Wheel's structure in 1972 and made a number of important discoveries, publishing his findings in "Astronomical Alignment of the Big Horn Medicine Wheel," Science 184 (1974): 1031-43. He found that cairns E and O were aligned in the direction of summer solstice sunrise, using cairn E for a backsight and cairn O as a foresight, and that cairns C and O were aligned in the direction of summer solstice sunset, using C as a backsight and O as a foresight.