  We have observed an extended region surrounding the first discovered galactic
superluminal source GRS 1915+105, seeking evidence of interaction between the
relativistic ejecta of that object and the interstellar medium. We find two
radio sources axisymmetrically aligned along the sub-arcsecond relativistic
ejecta of GRS 1915+105 and roughly 17' distant from it, which coincide with the
luminous IRAS sources 19124+1106 and 19132+1035. We have observed these sources
at centimeter (VLA), millimeter (IRAM 30m), and infrared (ISO, UKIRT, ESO/MPI
2.2m) wavelengths in both line and continuum emission. At centimeter
wavelengths a non-thermal jet-like feature aligned along the outflow axis is
located adjacent to the inner edge of the southern source. Strong density
enhancements are found in the millimeter tracers CO and H13CO+ at the positions
of both sources and some of the morphology is reminiscent of shock-like
interactions; however, linewidths are narrow. At infrared wavelengths strong
hydrogen recombination lines and weak lines of molecular hydrogen are observed
at the southern source. We discuss these results as possible evidence of the
sought-after interaction, both in terms of the regions undergoing ongoing
shock-heating and in terms of them being locations of shock-induced star
formation. The evidence for each of these is inconclusive. Millimeter line
mapping of a portion of W 50 where the relativistic jets of the X-ray binary SS
433 interact with the interstellar medium shows roughly similar morphology as
GRS 1915+105, suggesting that the phenomena observed at the IRAS sources may
not be unusual for such a long distance interaction.
