The Astronomy Research using the Cornell Infra-Red Imaging Spectrograph (ARCoIRIS) was made possible through supplemental funding from the National Science Foundation (NSF) to NOAO under the "Renewing Small Telescopes for Astronomical Research (ReSTAR)" Phase 1 program (Federal Award ID: 0936648), for which we are grateful. Its construction was a partnership between Cornell University (Dr. Terry Herter, PI) and NOAO. Cornell engaged the University of Virginia (Dr. John Wilson) to support the project. ARCoIRIS is the fourth generation of the TripleSpec instrument; two are already in use on the Palomar Observatory 200-inch Hale Telescope and the other on the Astronomy Research Consortium (ARC) 3.5-m telescope. The third is under construction at the California Institute of Technology (Kieth Matthews, PI) for the Keck II telescope. ARCoIRIS was installed at the f/8 Cassegrain focus on the Blanco 4-m telescope at CTIO during late-April 2015.