Photo of a water reservoir (IMAGE) University of Oklahoma Caption Hoover dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona. Credit Photo licensed by the University of Oklahoma via Shutterstock, image id: 391282072 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.