  The effects of oscillations of atmospheric muon neutrinos are observed in the
5.90 fiducial kiloton-year exposure of the Soudan 2 detector. An unbinned
maximum likelihood analysis of the neutrino L/E distribution has been carried
out using the Feldman-Cousins prescription. The probability of the no
oscillation hypothesis is 5.8x10-4. The 90% confidence allowed region in the
sin**(2theta), Delta m**2 plane is presented.
