  We systematically investigate new physics scenarios that can modify the
interactions between neutrinos and matter at upcoming tau neutrino telescopes,
which will test neutrino-proton collisions with energies $ \gtrsim 45~{\rm
TeV}$, and can provide unique insights to the elusive tau neutrino. At such
high energy scales, the impact of parton distribution functions of second and
third generations of quarks (usually suppressed) can be comparable to the
contribution of first generation with small momentum fraction, hence making tau
neutrino telescopes an excellent facility to probe new physics associated with
second and third families. Among an inclusive set of particle physics models,
we identify new physics scenarios at tree level that can give competitive
contributions to the neutrino cross sections while staying within laboratory
constraints: charged/neutral Higgs and leptoquarks. Our analysis is close to
the actual experimental configurations of the telescopes, and we perform a
$\chi^2$-analysis on the energy and angular distributions of the tau events. By
numerically solving the propagation equations of neutrino and tau fluxes in
matter, we obtain the sensitivities of representative upcoming tau neutrino
telescopes, GRAND, POEMMA and Trinity, to the charged Higgs and leptoquark
models. While each of the experiments can achieve a sensitivity better than the
current collider reaches for certain models, their combination is remarkably
complementary in probing the new physics. In particular, the new physics will
affect the energy and angular distributions in different ways at those
telescopes.
