A river that leads out into the ocean and goes through the whole island. Once a year, Magikarp from all over the Orange Islands come back here to their birthplace and after strengthening themselves up by swimming everywhere, try swimming upstream to the top of the river. They have to try to swim up currents and waterfalls to get to the top. The ones that do get to the top, swim around in the lake at the top until nighttime, then half of them evolve into Gyarados. Once the evolution process has ended, they swim back downstream and leave. Quincy T. Quackenpoker observes this.