How many plates interact near the pacific northwest?

The Pacific Northwest is primarily influenced by the interaction of three tectonic plates: the Juan de Fuca Plate, the North American Plate, and the Pacific Plate. The Juan de Fuca Plate subducts beneath the North American Plate along the Cascadia Subduction Zone, while the Pacific Plate interacts with the North American Plate along the San Andreas Fault to the south. These interactions contribute to significant geological activity, including earthquakes and volcanic eruptions in the region.