  We study the impact of astrophysically relevant nuclear isomers (astromers)
in the context of the rapid neutron capture process (r-process)
nucleosynthesis. We compute thermally mediated transition rates between
long-lived isomers and the corresponding ground states in neutron-rich nuclei.
We calculate the temperature-dependent beta-decay feeding factors which
represent the fraction of material going to each of the isomer and ground state
daughter species from the beta-decay parent species. We simulate
nucleosynthesis by including as separate species nuclear excited states with
measured terrestrial half-lives greater than 100 microseconds. We find a
variety of isomers throughout the chart of nuclides are populated, and we
identify those most likely to be influential. We comment on the capacity of
isomer production to alter radioactive heating in an r-process environment.
