The Lassen volcanic area lies at the southern extremity of the Cascade Range, which extends northward some from Lassen Peak within the park through Oregon and Washington and into British Columbia. Lassen Peak and the 16 other major Cascade Volcanoes form a segment of a ring of volcanoes that circle the Pacific Ocean known collectively as the 'Pacific Ring of Fire.' The Cascade Volcanoes are fed by heat generated as the Gorda and Juan de Fuca tectonic plates are being subducted below the much larger but lighter North American Plate. Lying some offshore, the spreading center of the Gorda Plate pushes out about of new crust toward the coast of Northernmost California and southern Oregon every year.