Cultural chronologies in the desert basins of the Southwestern U.S. rely on radiocarbon dates and ceramic sequences that are limited in terms of resolution. More precise dating methods, such as dendrochronology, have not been traditionally applied here due to the limited number of datable trees in arid locales.

Distributed amidst the petroglyphs at three of the largest Ancestral O’odham (Hohokam) petroglyph sites in Southern Arizona are assemblages of boulders that resonate when struck producing distinct bell-like sounds.  The visual traces of sound-making on large bell rocks and adjacent bedrock indicate they were not only chimed with percussion strikers to resonate with sound but also were abraded with a grinding motion to produce volumes of sound.