Coastal British Columbia, Canada, has the highest seismic hazard in the country due to convergent and transpressive deformation at offshore plate boundaries between the Pacific, Juan de Fuca and North American plates. Further landward, the crust of the North American plate is made up of several geologically unique terranes and is unusually thin. Investigating the geophysical features in this area can help us better constrain its tectonic history and the geophysical processes that are currently underway. Here, we conduct an analysis of teleseismic body-wave scattering data (i.e, receiver functions) recorded at stations across western coastal British Columbia including northern Vancouver Island and southeastern Alaska. Using these receiver functions, we perform a harmonic decomposition with respect to earthquake back-azimuths to determine the orientation of seismic anisotropy over a series of depth ranges, attributable to either mineral alignment or dipping structures. We find a coherent pattern of margin-parallel orientations at upper crustal depths that persist onto the mainland at distances ~420 km from the margin. Furthermore, dominant receiver function orientations at depth are attributed to dipping faults and interfaces, and fabrics due to lower crustal shearing or inherited from tectonic assembly along the margin. This work provides insight into the evolution of the margin and surrounding region, as well as the tectonic processes currently taking place. Identification of the dipping interfaces associated with the subducting Pacific and Juan de Fuca plates is important for assessment of earthquake and tsunami hazards.