<P> On the northerly boundary is a continuation of the Mid-Atlantic ridge called the Gakkel Ridge . The rest of the boundary in the far northwestern part of the plate extends into Siberia . This boundary continues from the end of the Gakkel Ridge as the Laptev Sea Rift, on to a transitional deformation zone in the Chersky Range, then the Ulakhan Fault between it and the Okhotsk Plate, and finally the Aleutian Trench to the end of the Queen Charlotte Fault system . </P> <P> The westerly boundary is the Queen Charlotte Fault running offshore along the coast of Alaska and the Cascadia subduction zone to the north, the San Andreas Fault through California, the East Pacific Rise in the Gulf of California, and the Middle America Trench to the south . </P> <P> On its western edge, the Farallon Plate has been subducting under the North American Plate since the Jurassic Period . The Farallon Plate has almost completely subducted beneath the western portion of the North American Plate leaving that part of the North American Plate in contact with the Pacific Plate as the San Andreas Fault . The Juan de Fuca, Explorer, Gorda, Rivera, Cocos and Nazca plates are remnants of the Farallon Plate . </P> <P> The boundary along the Gulf of California is complex . The Gulf is underlain by the Gulf of California Rift Zone, a series of rift basins and transform fault segments between the northern end of the East Pacific Rise in the mouth of the gulf to the San Andreas Fault system in the vicinity of the Salton Trough rift / Brawley seismic zone . </P>

In california is the boundary between the north american and pacific plates