Every four years, millions of sockeye salmon journey thousands of miles from the ocean back to their native spawning grounds in Canada's Fraser River. There, after eggs are laid, the parents die. Then the cycle begins anew as the next generation of salmon makes its way down the river and into the ocean. Subscribe for more National Geographic videos: goo.gl/utTCAg PRODUCER & VIDEOGRAPHER: Paul Colangelo SENIOR PRODUCER: Jeff Hertrick EDITOR: Nick Lunn