The Haloscope At Yale Sensitive To Axion CDM (HAYSTAC) Experiment is a microwave cavity search for cold dark matter (CDM) axions with masses above 20ueV. Located at Yale’s Wright Laboratory in New Haven, Connecticut, the HAYSTAC collaboration consists of members from Yale University, the University of California Berkeley, Lawrence Berkeley National Laboratory, and the University of Colorado at Boulder. HAYSTAC searches for axion dark matter in the galactic halo by searching for a resonant photon signal produced by axion conversion in a magnetic field. The detection of such a signal would provide important clues to the nature of dark matter and the constitution of the mass content of the universe.