Map: Amazon River and Watershed (IMAGE) University of Arizona Caption This map of South America shows the watershed of the Amazon River, the largest river system on Earth. The watershed, which stretches from the eastern slopes of the Andes to the Atlantic coast, covers 6.1 million square kilometers (2.4 million square miles) and includes nine countries. Credit Earth Observatory, NASA Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.