Magnetotransport of natural graphite and highly oriented pyrolytic graphite has been measured at mK temperatures. Quantum oscillations for both electron and hole carriers are observed with an orbital angular momentum quantum number up to N approximately 90. A remarkable agreement is obtained when comparing the data and the predictions of the Slonczewski-Weiss-McClure tight binding model for massive fermions. No evidence for Dirac fermions is observed in the transport data which are dominated by the crossing of the Landau bands at the Fermi level, corresponding to dE/dk_{z}=0, which occurs away from the H point where Dirac fermions are expected.