Bathymetry, side-looking sonar and magnetics data from the northern East Pacific Rise have been analyzed to determine the tectonic history of the Clipperton Fracture Zone (CFZ) and the Siqueiros Fracture Zone (SFZ) over the last 2--3 m.y. Results of tectonic reconstructions indicate a series of counterclockwise changes in spreading direction at ~2.5 Ma (1--2¿), ~1.5 Ma (1--2¿), and ~0.5 Ma (4--5¿). Along the right-stepping Clipperton Transform, the most recent change in spreading direction has resulted in fracture zone normal compression, which we propose has created a median ridge and transform-parallel troughs along the active transform fault. Volcanic intersection highs located near the ridge-transform intersections (RTI) of the CFZ are interpreted to be the result of fracture-zone-normal extension that has created pathways for magma emplacement into/onto the older lithosphere across from the RTI. Along the left-stepping SFZ, we propose the changes in spreading direction have generated extension across the transform and have resulted in the formation of intratransform spreading centers and flexural transverse ridges. Tectonic reconstructions indicate a single Euler pole is unable to describe the motion of the Pacific-Cocos plate boundary between the CFZ and SFZ during periods of spreading direction change since ~3 Ma. Transtensional transforms will adjust to a new spreading direction almost immediately, while transpressional transforms will experience compression for a period of time comparable to half the age offset of the compressional transform.¿ 1997 American Geophysical Union