  We study the propagation of ultra-high-energy cosmic rays (UHECR) in the
Galaxy, concentrating on the energy range below the ankle in the spectrum at 4
EeV. A Monte-Carlo method, based on analytical solutions to the time-dependent
diffusion problem, is used to account for intermittency by placing sources at
random locations. Assuming a source population that scales with baryon mass
density or star formation (e.g. long GRB), we derive constraints arising from
intermittency and the observational limits on the composition and anisotropy.
It is shown that the composition and anisotropy at 1e18 eV are difficult to
reproduce and require that either a) the particle mean free path is much
smaller than a gyroradius, implying the escape time is very long, b) the
composition is heavier than suggested by recent Auger data, c) the
ultrahigh-energy sub-ankle component is mostly extragalactic, or d) we are
living in a rare lull in the ultrahigh-energy cosmic-ray production, and the
current ultrahigh-energy cosmic-ray intensity is far below the Galactic time
average. We therefore recommend a strong observational focus on determining the
UHECR composition around 1e18 eV.
