 The next 108 planes serve as the fiducial region; particle showers beginning in them are neutrino interactions of interest.The final 72 planes are a "shower containment region" which observe the trailing portion of particle showers which began in the fiducial region.Finally, a 1.7 meter long "muon catcher" region is constructed of steel plates interleaved with 10 active planes of liquid scintillator.