  The MiniBooNE Collaboration reports initial results from a search for
$\bar{\nu}_{\mu}\to\bar{\nu}_e$ oscillations. A signal-blind analysis was
performed using a data sample corresponding to $3.39 \times 10^{20}$ protons on
target. The data are consistent with background prediction across the full
range of neutrino energy reconstructed assuming quasielastic scattering, $200 <
E_{\nu}^{QE} < 3000$ MeV: 144 electron-like events have been observed in this
energy range, compared to an expectation of $139.2 \pm 17.6$ events. No
significant excess of events has been observed, both at low energy, 200-475
MeV, and at high energy, 475-1250 MeV. The data are inconclusive with respect
to antineutrino oscillations suggested by data from the Liquid Scintillator
Neutrino Detector at Los Alamos National Laboratory.
