  We fit the HiRes ultra-high energy cosmic ray (UHECR) spectrum measurements
with broken power laws in order to identify features. These fits find the
previously observed feature known as the Ankle at 10**18.5 eV, as well as
evidence for a suppression at higher energies, above 10**19.8 eV. We use the
integral spectrum and the E_1/2 test to identify this high energy suppression
with the GZK suppression. Finally, we use a model of uniformly distributed
extragalactic proton sources together with a phenomenological model of the
galactic cosmic ray spectrum to compare the HiRes spectra to what should be
expected from the GZK suppression, and to measure how the extragalactic sources
must evolve and what the input spectral slope must be to fit the HiRes data.
Fits using updated spectra will be presented in Pune.
