  A previously-proposed method of constructing spatially-extended
gauge-invariant three-quark operators for use in Monte Carlo lattice QCD
calculations is tested, and a methodology for using these operators to extract
the energies of a large number of baryon states is developed. This work is part
of a long-term project undertaken by the Lattice Hadron Physics Collaboration
to carry out a first-principles calculation of the low-lying spectrum of QCD.
  These techniques are then applied in the construction of nucleon operators.
Correlation matrix elements between these operators are estimated using 200
configurations on a $12^3 \times 48$ anisotropic lattice in the quenched
approximation with unphysically heavy u, d quark masses (the pion mass is
approximately 700 MeV). After a change of basis operators using a variational
method is applied, the energies of up to eight states are extracted in each
symmetry channel.
  Although comparison with experiment is not justified, the pattern of levels
obtained qualitatively agrees with the observed spectrum. A comparison with
quark model predictions is also made; the quark model predicts more low-lying
even-parity states than this study yields, but both the quark model and this
study predict more odd-parity states near 2 GeV than currently observed in
experiments.
