The production of supersymmetric particles in ultrahigh-energy cosmic-ray interactions in the atmosphere is investigated. We find that the pair production and subsequent decay of a light (\ensuremath{\sim}3--5 GeV) gluino can lead to fluxes of neutral, weakly interacting superparticles which can be comparable to neutrino fluxes. Relevant processes for detecting photinos or scalar neutrinos in large neutrino detectors are discussed and several reactions with cross sections as large as those of ordinary \ensuremath{\nu} interactions are examined.