The Observatory's original 24-inch Alvan Clark Telescope is still in use today for public education. Lowell Observatory hosts 70,000 visitors per year who take guided daytime tours and view various wonders of the night sky through the Clark Telescope and other telescopes. It was founded in 1894 by astronomer Percival Lowell, and run for a time by his third cousin Guy Lowell of Boston's well-known Lowell family. The current trustee of Lowell Observatory is William Lowell Putnam, grandnephew of founder Percival Lowell and son of long-time trustee Roger Putnam.
The observatory operates several telescopes at two locations in Flagstaff. The main facility, located on Mars Hill just west of downtown Flagstaff, houses the original 24-inch (0.61-meter) Clark Refracting Telescope, although its role today is as a public education tool and not research. The telescope, built in 1896 for $20,000, was assembled in Boston by Alvan Clark and then shipped by train to Flagstaff. Also located on the Mars Hill campus is the 13-inch (0.33-meter) Pluto Discovery Telescope, used by Clyde Tombaugh in 1930 to discover the dwarf planet Pluto.
Lowell Observatory currently operates four research telescopes at its Anderson Mesa dark sky site, located 12 miles southeast of Flagstaff, including the 72-inch (1.8-meter) Perkins Telescope (in partnership with Boston University) and the 42-inch (1.1-meter) John S. Hall Telescope. Lowell is a partner with the United States Naval Observatory and NRL in the Navy Prototype Optical Interferometer (NPOI) also located at that site. The Observatory also operates smaller research telescopes at its historic site on Mars Hill and in Australia and Chile. Lowell Observatory is currently building the 4.2-meter Discovery Channel Telescope in partnership with Discovery Communications, Inc.
Lowell Observatory is building a major new telescope in partnership with Discovery Communications near Happy Jack in northern Arizona. The telescope, located within the Mogollon Rim Ranger District of the Coconino National Forest, is expected to be the fifth largest in the continental United States and will allow Lowell astronomers to enter new research areas and conduct existing programs more effectively and efficiently. The DCT and the research it enables also will be the focus of ongoing informative and educational television programs about astronomy, science, and technology airing on Discovery networks In addition, the Discovery Channel Telescope at Lowell Observatory is expected to have a significant educational and economic impact within the state.