Perkins Observatory were both growing. Light pollution therefore became increasingly problematic. So in 1961 the Perkins Telescope was moved to Lowell Observatory in Flagstaff, Arizona. Lowell is the largest private observatory (non-university or government affiliated) in the world. Through the end of the 20th century, the Perkins Telescope was the observatory’s largest instrument. Observing time on this instrument was shared between Lowell astronomers and the Ohio State University. The telescope at Perkins was immediately replaced with a cassegrain reflector telescope. It was donated by Michael R. Schottland, an entrepreneur from Martinsville, Virginia. At that time it was the largest privately owned telescope
National Optical Astronomy Observatory shape the System and gain steady, state-of-the-art research capabilities of all apertures for open, merit based science. A future major capability for the US system is an Extremely Large Telescope with diameter up to 30 meters. Two private consortia are currently working on such projects which may be operational before the end of the decade. These are the Thirty Meter Telescope and Giant Magellan Telescope. NOAO is working with both projects in planning for potential future involvement of the broad US community through operational support funding by the NSF. National Optical Astronomy Observatory The National Optical Astronomy Observatory (NOAO) is