List of the largest optical telescopes in North America
Name/Observatory Location Lens diameter Focal length Built Comments
Yerkes Observatory Williams Bay , Wisconsin , USA 102 cm ( 40″ ) 19.4 m ( 62′ ) 1897 Largest in current operation
James Lick telescope Lick Observatory Mount Hamilton , California , USA 91 cm ( 36″ ) 17.6 m 1888
William Thaw Telescope Allegheny Observatory Pittsburgh , Pennsylvania , USA 76 cm ( 30″ ) 14.1 m 1914 Brashear made , photographic
Leander McCormick Observatory Charlottesville , Virginia , USA 66 cm ( 26 ) 9.9 m 1884 completed c. 1874 , installed 1884
U.S . Naval Observatory Foggy Bottom Washington , DC , USA moved to Northwest , Washington , D.C. , 1893 66 cm ( 26 ) 9.9 m 1873 Largest refractor in 1873 . Alvan Clark & Sons mounting replaced with Warner & Swasey mounting in 1893
Sproul Observatory Pennsylvania , USA 61 cm ( 24″ ) 11.0 m ( 36 ft ) 1911 Currently under restoration to be re-installed in Northwest Arkansas
Lowell Observatory Arizona , USA 61 cm ( 24″ ) 9.75 m ( 32 ft ) 1894 Alvan Clark & Sons telescope
Refractors
Some of the big traditional refractors ( telescope with lens ) in North America :
List of the largest optical telescopes in the contiguous United States ranks telescopes of North America, a continent in the northern hemisphere of Earth.