Long ago, when most of the world was water, Great Spirit decided to make a beautiful land with lakes and rivers that turtles carried on their backs. One day the turtles began to argue and three of the turtles began to swim towards the rising sun while three began to swim towards the setting sun. The earth shook! It cracked with a loud noise. The turtles could not swim far, because the land on their backs was heavy. When they saw that they could not swim far enough to get away from each other they stopped arguing and made up. But every once in a while, the turtles that hold up the earth, argue again, and each time they do the earth shakes.
Legend of the Gabrielaino Indians of Southern California. Accessed from: http://www.topangaonline.com/nativam/turtles.html