  The NuMI neutrino beam line and the MINOS experiment represent a major
investment of US High Energy Physics in the area of neutrino physics. The
forthcoming results could decisively establish neutrino oscillations as the
underlying physics mechanism for the atmospheric $\numu$ deficit and provide a
precise measurement of the corresponding oscillation parameters, $\dmsq23$ and
$\sinsq2t23$.neutrino sector may well be within our reach. The full potential
of the NuMI neutrino beam can be exploited by complementing the MINOS detector,
under construction, with a new detector(s) placed at some off-axis position and
collecting data in parallel with MINOS. The first phase of the proposed program
includes a new detector, optimized for $\nue$ detection, with a fiducial mass
of the order of 20 kton and exposed to neutrino and antineutrino beams. In a
five year run its sensitivity to the $\numutonue$ oscillations will be at least
a factor of ten beyond the current limit.
  The future direction of the program will depend on the results of this first
phase, but it is very likely that it will be a combination of a significant
increase of the neutrino beam intensity via an upgraded proton source and an
increase of the detector mass by a factor of five or so. Depending on the
circumstances, the goals of Phase II may be a further increase of the
sensitivity of a search for $\numutonue$ oscillations, or, perhaps, a
measurement of the CP violating phase $\delta$ in the lepton sector.
