  I describe the current state of our knowledge of the mapping between the
initial masses of stars and the compact objects -- particularly neutron stars
and black holes -- that they produce. Most of that knowledge is theoretical in
nature, and relies on uncertain assumptions about mass loss through winds,
binary mass transfer, and the amount of mass ejected during a supernovae.
Observational constraints on the initial masses of stars that produce neutron
stars and black holes is scarce. They fall into three general categories: (1)
models of the stars that produced the supernova remnants associated with known
compact objects, (2) scenarios through with high mass X-ray binaries were
produced, and (3) associations between compact objects and coeval clusters of
stars for which the minimum masses of stars that have undergone supernovae are
known. I focus on the last category as the most promising in the near term. I
describe three highly-magnetized neutron stars that have been associated with
progenitors that had initial masses of $>$30\msun, and evaluate the prospects
of finding further associations between star clusters and compact objects.
