  The diffuse gamma radiation arising from the interaction of cosmic ray
particles with matter and radiation in the Galaxy is one of the few probes
available to study the origin of the cosmic rays. Milagro is a water Cherenkov
detector that continuously views the entire overhead sky. The large
field-of-view combined with the long observation time makes Milagro the most
sensitive instrument available for the study of large, low surface brightness
sources such as the diffuse gamma radiation arising from interactions of cosmic
radiation with interstellar matter. In this paper we present spatial and flux
measurements of TeV gamma-ray emission from the Cygnus Region. The TeV image
shows at least one new source MGRO J2019+37 as well as correlations with the
matter density in the region as would be expected from cosmic-ray proton
interactions. However, the TeV gamma-ray flux as measured at ~12 TeV from the
Cygnus region (after excluding MGRO J2019+37) exceeds that predicted from a
conventional model of cosmic ray production and propagation. This observation
indicates the existence of either hard-spectrum cosmic-ray sources and/or other
sources of TeV gamma rays in the region.
