Tumamoc Hill, a butte in the Tucson Mountains west of downtown Tucson, has been important both as an ancient cultural site and as a center of ecological research. Once home to the Hohokam, it contains the earliest known trincheras village, hundreds of petroglyphs, and a prehistoric garden, and it remained significant to O'odham, Hopi, and Apache communities. Its modern scientific role began in 1903 with the Carnegie Institution's Desert Laboratory and ecological reserve, where researchers helped shape ecology in the United States. Now managed by the University of Arizona, it remains a research preserve, a National Historic Landmark, and a popular public walking route.