  Considerations of the collision losses for protons traversing the 2.7 K black
body microwave radiation field have led to the conclusion that the highest
energy cosmic rays, those observed at $\geq 10^{20}$ eV, must come from sources
within the present epoch. In light of this constraint, it is here suggested
that these particles may be accelerated near the event horizons of spinning
supermassive black holes associated with presently inactive quasar remnants.
The required emf is generated by the black hole induced rotation of externally
supplied magnetic field lines threading the horizon. Producing the observed
flux of the highest energy cosmic rays would constitute a negligible drain on
the black hole dynamo. Observations with upcoming air shower arrays and space
missions may lead to the identification of candidate dormant galaxies which
harbor such black holes. Although the highest energy events observed so far are
accounted for within the context of this scenario, a spectral upper bound at
$\sim 10^{21}$ eV is expected since the acceleration to higher energies appears
to be precluded, on general grounds.
