  The next generation of neutrino oscillation experiments, JUNO, DUNE, and HK,
are under construction now and will collect data over the next decade and
beyond. As there are no approved plans to follow up this program with more
advanced neutrino oscillation experiments, we consider here one option that had
gained considerable interest more than a decade ago: a neutrino factory. Such
an experiment uses stored muons in a racetrack configuration with extremely
well characterized decays reducing systematic uncertainties and providing for
more oscillation channels. Such a machine could also be one step towards a high
energy muon collider program. We consider a long-baseline configuration to SURF
using the DUNE far detectors or modifications thereof, and compare the expected
sensitivities to the three-flavor oscillation parameters to the anticipated
results from DUNE and HK. We find that a neutrino factory can improve our
understanding of CP violation and also aid in disentangling the complicated
flavor puzzle.
