Astronomical observations in the millimeter and sub-millimeter regions are performed at the two facilities of the Arizona Radio Observatory (ARO). The Sub-Millimeter Telescope (SMT) located on Mount Graham utilizes 3 heterodyne SIS receivers to cover 3 of the 4 atmospheric windows from 210 to 720 GHz and soon a new receiver will cover the remaining window. The 12-Meter telescope located on Kitt Peak use 3 heterodyne SIS receivers to the cover the 2 windows from 68 to 180 GHz. All receivers now employ orthogonal polarization optics and soon 4 will utilize wideband dual channel sideband separating mixer technology. Presented here are new instrumentation developments and recent scientific results from the ARO.