create a variation of floodplain vegetation and succession throughout the park. New deposits such as sandbars and accretions adjacent to the riverbanks are covered with the pioneer species: annual weeds, short-lived grasses, sedges, and seedling willow and cottonwood. On higher above the water table, larger willow and cottonwood trees dominate. The floodplain forest includes larger cottonwoods on the highest banks and islands. The understory in the cottonwood forest is primarily dogwood, sumac, wild grape, and poison ivy. The sparse vegetation under the mature cottonwoods consists mostly of scouring rush, Kentucky bluegrass, smooth brome, and other invasive grasses and weeds. Above the floodplain, there is a mixed forest and agricultural fields. The forests on the adjoining bluffs are primarily hardwoods with the slopes covered by a dense growth of oak, ash, mulberry, and walnut, with burr oak as the dominant species. Wildlife is plentiful. Since the days of Lewis and Clark the larger mammals have disappeared, including the grizzly bear, bison, and elk. Small mammals, including mice, voles, bats, rats, and ground squirrels make up the bulk of the species within the park. Deer are often seen on private property along the banks. The American bald eagle has been gradually increasing throughout the park. Two other birds, the piping plover (northern Great Plains population) and the least tern (interior population), are still listed as threatened and endangered respectively. There are over 250 bird species identified within the riverway. Threatened species The National Park Service works alongside the U.S. Army Corps of Engineers and U.S. Fish and Wildlife Service to help manage habitat for threatened and endangered species, especially the Piping plover, Least tern, and Pallid sturgeon. Since the establishments of the dams on the Missouri River these species and their population numbers have decreased. Habitat restoration and resource protection measures have been in place to help rebound these numbers. Often during the summer months sandbars are signed as "Closed" to help protect critical habitat, fines and other penalties can be imposed for violators. Things to do Recreational and educational opportunities abound at the Missouri National Recreational River. Fishing and hunting are popular actives. Walleye and catfish are the most popular species. Canoeing and kayaking are growing in popularity, and ranger-guided excursions are scheduled often during the summer. Parks and recreation areas As a "partnership park", the National Park Service (NPS) works closely with local and state agencies to help manage the