We investigate the utility of cosmological and astrophysical observations for distinguishing between supersymmetric theories. In particular we consider 276 pairs of models that give rise to nearly identical patterns of observables at hadron colliders. Despite inherent uncertainties in such things as the local halo density model, or background rates from astrophysical sources, we find observations associated with stable relic neutralinos can be a surprisingly effective discriminant between candidate theories. We focus attention on neutralino scattering experiments (direct detection of relic neutralinos) and observations of gamma-rays from relic neutralino annihilation (indirect detection experiments). With extremely conservative physics assumptions and background estimates we find 101 of the 276 degenerate pairs can be distinguished. Using slightly more optimistic assumptions about background rates increases this number to 186 of the 276 pairs. In the direct detection arena the ability to distinguish between models will be dependent on further progress in addressing uncertainty in nuclear matrix elements. For observations in the indirect detection arena we discuss the sensitivity of these results to additional assumptions made about the cosmological density of neutralinos and the galactic halo profile. We also comment on the complementarity of this study to recent work investigating these same pairs at a 500 GeV linear collider.