High energy gamma rays probe the most extreme astrophysical environments
including those that produce the highest energy cosmic-ray particles.
With its large field of view and long observation time, the Milagro
Gamma-Ray Observatory -- a water Cherenkov detector in the Jemez
Mountains near LANL -- is an ideal instrument for surveying large
regions of the Northern Hemisphere sky for these gamma rays.
I will discuss the Milagro instrument, and how we
are measuring the gamma ray emission, in particular from the Galactic
Plane. In this region, the Milagro experiment has previously observed
eight sources or source candidates. I will report the positions and
fluxes of these locations as measured by Milagro. The event excesses
from these sources can be subtracted from the total event excess
measured in the Galactic Plane region to estimate the amount of diffuse
emission. I will also report the resulting diffuse emission and compare
it to predictions of a model, which calculates the expected gamma-ray
emissivity due to cosmic-ray interactions with matter.
Finally, I will describe future prospects for high energy gamma ray
astrophysics with the next generation of water Cherenkov detectors,
HAWC.