What is the name of type boundary that California on?

The type of plate boundary that California is on is called a transform boundary. Transform boundaries occur where two tectonic plates are sliding past each other horizontally, rather than moving towards or away from each other. The San Andreas Fault, which runs through California, is a famous example of a transform boundary. Along the San Andreas Fault, the Pacific Plate and the North American Plate are moving past each other in opposite directions, which creates significant seismic activity and the potential for major earthquakes.