Beneath the creosote and cactus around the Desert Museum, battered stones, sharp-edged pieces of rock, stones for grinding, and fragments of pottery can be found. The Hohokam left these artifacts at the site over 600 years ago. Scatters of prehistoric stonetools and pottery like these are common in the Tucson Mountains; they number in the hundreds, maybe even the thousands. Most of the sites show no signs of habitation-no houses, no fire pits.