Map of the USGS NPR-A Assessment (IMAGE) U.S. Geological Survey Caption This map shows the assessment units of the USGS assessment of the National Petroleum Reserve-Alaska and adjacent state and Tribal lands and waters. Credit USGS 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.