The Haskell-Baker Wetlands is a nature preserve and artificially sustained wetland, spanning approximately 640 acres (2.6 km2) south of Lawrence, Kansas, United States. It is associated with the Wakarusa River and sustained by levees and flood controls built in the 1990s. In 1969, the National Park Service declared the wetlands a National Natural Landmark. The wetlands support 413 documented species of vascular plant, 265 species of bird, and 61 additional vertebrate species.