  Limits on $\nu_\mu \to \nu_e$ and $\bar\nu_\mu \to \bar\nu_e$ oscillations
are extracted using the NuTeV detector with sign-selected $\nu_\mu$ and
$\nub_\mu$ beams. In $\nub_\mu$ mode, for the case of $\sin^2 2\alpha = 1$,
$\Delta m^2 > 2.6$ ${\rm eV^2}$ is excluded, and for $\Delta m^2 \gg 1000$
${\rm eV^2}$, $\sin^2 2\alpha > 1.1 \times 10^{-3}$. The NuTeV data exclude the
high $\Delta m^2$ end of $\bar\nu_\mu \to \bar\nu_e$ oscillations parameters
favored by the LSND experiment without the need to assume that the oscillation
parameters for $\nu$ and $\nub$ are the same. We present the most stringent
experimental limits for $\nu_\mu (\bar{\nu}_\mu) \to \nu_e (\bar{\nu}_e)$
oscillations in the large $\Delta m^2$ region.
