  We report on the discovery of compact, narrow OH line emission from the
hydroxl molecule at 1720 MHz toward the extended TeV source J1834-087. The
origin of this high energy emission is unknown; it could be powered by one or
more candidate neutron stars (leptonic) or by cosmic rays interacting with
dense gas (hadronic). The OH emission is detected near the center of J1834-087,
coincident with the radio continuum of the supernova remnant W41, and the
radial velocity of the line is the same velocity as a giant molecular cloud
along the line of sight. We argue that the OH is maser emission stimulated by
the interaction of the W41 shock with the molecular cloud. The known
correlation between gamma-ray bright supernova remnants and OH masers favors a
hadronic interpretation for this high energy emission.
