In the spring of 1999 respected Salish elder Dobie Tom visited a boulder with markings on a hillside meadow near Bonney Lake, Washington, about 20 miles southeast of Tacoma. Tom identified the markings on top of the massive glacial erratic, rediscovered during planning for a nearby housing development, as a map of the Puyallup Valley. The bowl-like depression in the center of the top represented the original Lake Tapps to the northeast, he said.
The following year the property owner contracted two researchers from the community college. Using computer models Gerald Hedlund and Dennis Regan decided the twenty human made depressions (cupules? a mortar?) on the stone’s flat surface indicated the stone, with use sticks and cords, could have been an observatory for determining seasonal changes and predicting sun, moon, and star alignments and possibly as sight lines to mountains, including Mount Rainier. They named it Skystone.
E.C. Krupp, astronomer, director of the Griffith Observatory, and a specialist in the field of archaeoastronomy, said native peoples probably already knew when the solstices occurred by observing the heavens. "The site sounds to me like it's for rituals or an educational site," and added more proof is needed to accept Skystone as an old observatory.
The Puyallup Tribal Council called the find "an exciting rediscovery…considering the rock carving is located in the Tribe’s traditional usual and accustomed area" and called for a plan to protect "this fascinating cultural feature."
Notably this petroglyph boulder is not identified in rock art surveys that include Western Washington (Lundy 1974, Hill and Hill1974, McClure 1978, Wellman 1979, Leen 1981). I compiled the above summary through local newspaper stories (1999-2009) and fragments of references on city and tribal websites. So, ambiguity lingers beyond what can be recorded in this modest blog posting. Isn’t that how rock art works?
Photos (November 2013) and details: Bonney Lake Skystone Petroglyph