We discuss the possible existence of an observational window, in the TeV-PeV energy range, for the detection of prompt neutrinos from the decay of charmed particles produced in cosmic ray interactions with the atmosphere. We calculate the event rates for muon and tau neutrinos of heavy quark, mostly charm, origin. We argue that their prompt fluxes are observable in a kilometer-scale neutrino telescope, even though the calculations are subjected to large uncertainties, which we quantify. We raise the possibility that a small component of prompt neutrinos may already be present in the observed samples of current experiments. We also discuss the interplay of the predicted fluxes with those produced by the flavor oscillation of conventional atmospheric neutrinos, and by anticipated cosmic sources.

9 pages, Revtex (single-spaced), 2 postscript figures