Dams alter rivers in ways that reduce the creation of natural sandbars, which is bad news for threatened Piping Plovers that depend on them for nesting habitat. Between 2004 and 2009, more than 200 hectares of engineered sandbars were built along the Missouri River to address the problem—but how does this engineered habitat compare to the real thing? A new study from The Condor: Ornithological Applications takes advantage of a natural experiment created by the region’s 2011 floods, demonstrating that the engineered habitat doesn’t provide the benefits of sandbars created by nature.