A concentration of temporary and permanent long-period stations has been used to record Rayleigh and Love waves over a region bounded by Vancouver Island in the west and a line approximately 400 km to the east. Phase-velocity information for both Rayleigh and Love waves has been calculated and inverted to provide estimates of models along the profiles. Generalized matrix inversion techniques have been employed to set confidence limits on the models. No significant upper-mantle low-velocity zone was detected under Vancouver Island or the adjacent coastal region. To the east a shallow upper-mantle low-velocity zone dipping to the northeast was required to fit the data. The transition from crust to mantle was sharper and more prominent to the northeast than to the southwest.