Which fault is the best-known transform boundary between the Pacific and North American plates?

The San Andreas Fault is the best-known transform boundary between the Pacific and North American plates.

It is a continental transform fault system in California where the two plates slide mainly horizontally past one another. This motion is called right-lateral strike-slip movement: from one side of the fault, the opposite side appears to move to the right.

The fault extends for roughly 1,200 kilometers through California and is divided into sections with different earthquake histories. Some sections have produced major earthquakes, while parts of the central fault have experienced frequent creep that releases strain gradually.

The San Andreas Fault is not a single straight crack with identical behavior everywhere. It is a complex system of strands, and many California earthquakes occur on other nearby faults.