  We present a four-neutrino model with three active neutrinos and one sterile
neutrino which naturally has maximal $\nu_\mu\to\nu_\tau$ oscillations of
atmospheric neutrinos and can explain the solar neutrino and LSND results. The
model predicts $\nu_e \to \nu_\tau$ and $\nu_e \to \nu_\mu$ oscillations in
long-baseline experiments with $L/E \gg 1$ km/GeV with amplitudes that are
determined by the LSND oscillation amplitude and argument controlled by the
atmospheric $\delta m^2$.
