Yellowstone Wolves at Play (IMAGE) U.S. National Science Foundation Caption These are sibling members of Yellowstone National Park's Druid Peak Pack at play. Credit Daniel Stahler/NPS. 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.