The Peace-Athabasca Delta is a large freshwater, inland delta in northeastern Alberta located where the Peace and Athabasca Rivers join the Slave River. The Birch River also flows into this region. The marshes, lakes and mud flats of this area are an important habitat for waterfowl nesting and provides a staging area for migration. As many as one million ducks, geese and swans pass through this area in the fall. The grass and sedge meadows of this area provide habitat for several thousand Wood and Plains Buffalo. The endangered Whooping Crane migrates through the delta on its way to its nearby nesting area.