  We propose a method to investigate the scenario that cosmic relic neutrinos
are highly clustered around stars and galaxies, or dark-matter clusters, rather
than uniformly distributed in the universe. Such a scenario can be detected or
constrained by the interaction of high energy cosmic ray protons and nuclei
with the cosmic neutrinos. There should be observable signature in the energy
spectra of cosmic ray protons and nuclei for a neutrino clustering factor
beyond $10^{13}$. We provide a relation on the signature onset positions
between proton and nuclei spectra, and discuss possible support from existing
experiments. It is also suggested that the relative abundance of cosmic ray
nuclei may detect or constrain the cosmic neutrinos with smaller clustering.
