  Charged current scattering of \nu_\mu on ^{12}C has been studied using a
\pi^+ decay-in-flight \nu_\mu beam at the Los Alamos Neutron Science Center. A
sample of 66.9+-9.1 events satisfying criteria for the exclusive reaction
^{12}C(\nu_\mu,\mu^-)^{12}N_{g.s.} was obtained using a large liquid
scintillator neutrino detector. The observed flux-averaged cross section
(5.6+-0.8+-1.0) x 10^{-41} cm^2 agrees well with reliable theoretical
expectations. A measurement was also obtained for the inclusive cross section
to all accessible ^{12}N states ^{12}C(\nu_\mu,\mu^-)X. This flux-averaged
cross section is (10.6+-0.3+-1.8) x 10^{-40} cm^2 which is lower than present
theoretical calculations.
