Horizontal Drilling in the USA (IMAGE) American Geophysical Union Caption This image shows percent of hydraulically fractured wells that were horizontally drilled from January 2011 through August 2014 in watersheds in the United States (n=47,646). Credit Credit: Tanya Gallegos 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.