This work reports quantum mechanical and semiclassical WKB calculations for energies and wave functions of high-lying 2 Σ states of H + 2 in atomic units. The highlying states presented lie in an unexplored regime, corresponding asymptotically to H (n ≤ 145) plus a proton, with R ≤ 120, 000 a 0 . We compare quantum mechanical energies, spectroscopic constants, dipole matrix elements, and phases with semiclassical results and demonstrate a good level of agreement. The quantum mechanical phases are determined by using Milne's phase-amplitude procedure. Our semiclassical energies for low-lying states are compared with those published previously in the literature.