The H-3 potential energy surface has been calculated using the Cashion-Hershbach (CH) potential which contains all orders of two-body Coulomb, exchange, and overlap terms. For collinear configurations, the dominant three-body contribution comes from the Axilrod-Teller-Muto triple-dipole dispersion energy. By adding only this term, properly damped, the saddle point region potential agrees with recent ab initio calculations to within 9 x 10(-5) a.u. (0.06 kcal/mole).