Megaflood Dunes (IMAGE) University of Washington Caption This map shows the flood-formed dunes in the area of Wasilla, Alaska. Flood waters flowed from right to left across the image. The dunes reach more than 110 feet high and are spaced more than a half-mile apart. Credit Michael Wiedmer Usage Restrictions News use only. 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.