  Spiral arm spurs are prominent features that have been observed in extinction
and 8$\mu$m emission in nearby galaxies. In order to understand their molecular
gas properties, we used the Owens Valley Radio Observatory to map the
CO(J=1--0) emission in three spurs emanating from the inner northwestern spiral
arm of M51. We report CO detections from all three spurs. The molecular gas
mass and surface density are M$_{H2} \sim3\times10^6$ M$_{\sun}$ and
$\Sigma_{H2} \sim$50 M$_{\sun}$ pc$^{-2}$. Thus, relative to the spiral arms,
the spurs are extremely weak features. However, since the spurs are extended
perpendicular to the spiral arms for $\sim$500 pc and contain adequate fuel for
star formation, they may be the birthplace for observed inter-arm HII regions.
This reduces the requirement for the significant time delay that would be
otherwise needed if the inter-arm star formation was initiated in the spiral
arms. Larger maps of galaxies at similar depth are required to further
understand the formation and evolution of these spurs and their role in star
formation - such data should be forthcoming with the new CARMA and future ALMA
telescopes and can be compared to several recent numerical simulations that
have been examining the evolution of spiral arm spurs.
