The Juan de Fuca Ridge is an underwater mountain range located in the northeastern Pacific Ocean. It is a divergent tectonic plate boundary between the Juan de Fuca Plate and the North American Plate. This ridge is known for its volcanic activity and hydrothermal vents, which support unique ecosystems. The ridge extends approximately 500 kilometers (310 miles) and is part of the larger Cascadia Subduction Zone. It plays a significant role in the geology of the region, influencing seismic activity and the formation of new oceanic crust as magma rises from the mantle.