  The MiniBooNE experiment at Fermilab reports results from an analysis of the
combined $\nu_e$ and $\bar \nu_e$ appearance data from $6.46 \times 10^{20}$
protons on target in neutrino mode and $11.27 \times 10^{20}$ protons on target
in antineutrino mode. A total excess of $240.3 \pm 34.5 \pm 52.6$ events ($3.8
\sigma$) is observed from combining the two data sets in the energy range
$200<E_\nu^{QE}<1250$ MeV. In a combined fit for CP-conserving $\nu_\mu
\rightarrow \nu_e$ and $\bar{\nu}_{\mu}\rightarrow\bar{\nu}_e$ oscillations via
a two-neutrino model, the background-only fit has a $\chi^2$-probability of
0.03% relative to the best oscillation fit. The data are consistent with
neutrino oscillations in the $0.01 < \Delta m^2 < 1.0$ eV$^2$ range and with
the evidence for antineutrino oscillations from the Liquid Scintillator
Neutrino Detector (LSND).
