The first major astronomical facility of the National Observatory was the No. 1 36-inch, which became operational in March 1960. Since then, the telescope has been used for a wealth of spectroscopic, photographic, and photometric programs.
A CCD camera was installed in 1984, and quickly became the instrument of choice for observers doing deep, wide-field imaging and photometry.
The No. 2 36-inch telescope became operational in 1966 (shortly after the 84-inch was commissioned), and has primarily been used for photoelectric photometry.
During the summer of 1990 the site of the No. 1 was cleared for use by the 3.5-m WIYN telescope, and a single 0.9m facility was made using the best of both telescopes; the old No. 1 telescope is housed in the old No. 2 dome. At that time, operation of the telescope was moved to a control room located downstairs, in order to remove heat-sources from the telescope area, and in order to provide a more comfortable and efficient observing environment.
In 2001 the WIYN Consortium took over operations of the 0.9m telescope. Upgrading the control system and installing new motors and encoders in all axes was performed by Astronomical Consultants and Equipment, Inc.