Cosmic muons are produced high in earth’s atmosphere by collision of nuclei of air molecules by high-energy primary cosmic rays.  Many of these muons make it to earth’s surface before decaying into electrons.  We have developed an 8-detector system to measure the trajectories of these cosmic muons to produce a 2-dimensional color map of the muon flux in the upper atmosphere.  Students helped build the array of detectors and have opportunity to participate in cosmic muon research.