Heavy rain triggered Potomac River floodwaters to rage through Great Falls National Park in McClean, Virginia, on Sunday, May 20. Water levels were so high that rocks that normally can be seen throughout the area were covered with water.Six inches of rain fell over the course of eight days in the Washington, DC region, a news report said. The National Park Service had to close some trails on the Maryland side of the river at the falls on Sunday because of the high water.Downstream, East Potomac Park in Washington, DC was flooded with walking and bike paths under water. Credit: National Park Service via Storyful