If item number one on your summer to-do list is to witness the booming waterfalls of Yosemite National Park, you're in for a treat. Water levels appear to have rebounded from four years of drought and we're now in a window of peak waterfall conditions.

United States Geological Survey numbers indicate water under the Pohono Bridge at the west end of the Yosemite Valley has been climbing, and reaching heights not seen since 2012. The water level has peaked between May 19th and June 29th in recent years, but the high water mark hasn't crested above 8 feet in four years, according to the USGS. The river has approached that depth in recent weeks, as seen on this chart of river heights recorded since May of 2010: