Green Bank Interferometer radio telescopes, seen from a high elevation on the Green Bank Telescope (GBT) as fog lifts over the surrounding landscape. The outer members of the Green Bank Interferometer (GBI), called 85-3 and 85-2, are 85-foot dish radio telescopes that are used with a third, the Howard E. Tatel telescope, to form a northeast-southwest aligned array. The GBI was active in the 1960s and 1970s as a testbed for the Very Large Array (VLA). These telescopes are located at the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia, USA. Photographed after 2001, when the GBT was completed. Since 2016, the site has been operated as Green Bank Observatory.