Tumamoc Hill () is a butte located immediately west of A Mountain and downtown Tucson, Arizona. It is home to many radio, television, and public safety transmitters. The 860-acre ecological reserve and U.S. National Historic Landmark was established by the Carnegie Institution in 1903. The University of Arizona (UA) owns a preserve and leases another as a research and education facility. The Steward Observatory maintains a small astronomical observatory with a telescope on the hill. Besides being a prominent landmark, Tumamoc Hill has a long and varied history, and is currently an important site for ecological and anthropological research as well as a refuge and a recreational option for the people of Tucson. The Desert Laboratory located on Tumamoc welcomed a new director, Ben Wilder, as of 2018.