The Electron Paramagnetic Resonance Facility (EPR) facility at Caltech is a multi-user magnetic resonance spectroscopy facility that provides access to state of the art instrumentation for characterization of samples containing paramagnetic species (e.g. organic radicals, open-shell transition metal complexes, defects in materials, spin labeled biomolecules, etc.). Our primary objective is to provide a broad suite of continuous-wave (CW) and pulse EPR spectroscopies for the detailed characterization of paramagnetic species to the Caltech community and surrounding institutions. The facility provides the appropriate equipment and expertise for determination of optimal experiments suited to the specific subject of study, and analysis of data acquired towards elucidation of the geometric and electronic structure of the species of interest.