We report on a high-statistics bubble-chamber experiment using the Fermilab 15-ft bubble chamber filled with a heavy neon/hydrogen mixture exposed to a wide-band neutrino beam. In a sample of 106 000 ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ >0.3 GeV/c) and a negative muon were observed. After corrections, the rate for opposite-sign dilepton production for ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ charged-current events is (0.52\ifmmode\pm\else\textpm\fi{}0.09)%. The ${E}_{\ensuremath{\nu}}$ dependence of this rate from threshold to \ensuremath{\approxeq}200 GeV is presented. The kinematic distributions and strange-particle content of the dilepton events are consistent with those expected from charm-particle production in neutrino interactions. A total of 58 neutral strange particles (\ensuremath{\Lambda}\ensuremath{\rightarrow}p${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$, ${K}_{S}^{0}$\ensuremath{\rightarrow}${\ensuremath{\pi}}^{+}$${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$) are observed in these events, where less than 16 are expected from conventional charged-current interactions. The presence of a significant excess of \ensuremath{\Lambda}'s is evidence for substantial charmed-baryon production.