  We compare the tau neutrino flux arising from the galaxy and the earth
atmosphere for 10^3 < E/GeV < 10^11. The intrinsic and oscillated tau neutrino
fluxes from both sources are calculated. The intrinsic galactic \nu_{\tau} flux
(E > 10^3 GeV) is calculated by considering the interactions of high-energy
cosmic-rays with the matter present in our galaxy, whereas the oscillated
galactic \nu_{\tau} flux is coming from the oscillation of the galactic
\nu_{\mu} flux. For the intrinsic atmospheric \nu_{\tau} flux, we extend the
validity of a previous calculation from E < 10^6 GeV up to E < 10^11 GeV. The
oscillated atmospheric \nu_{\tau} flux is, on the other hand, rather
suppressed. We find that, for 10^3 < E/GeV < 5\cdot 10^7, the oscillated
\nu_{\tau} flux along the galactic plane dominates over the maximal intrinsic
atmospheric \nu_{\tau} flux, i.e., the flux along the horizontal direction. We
also briefly mention the presently envisaged prospects for observing these
high-energy tau neutrinos.
