The 1930s era building of Bagnell Dam and Ameren Missouri's Osage hydroelectric plant created a range of wildlife preservation opportunities at the now popular Lake of the Ozarks.

One of the largest heron rookeries in the state exists about 10 miles downstream of the Osage Plant, and the lake area is important for migrating ducks and wintering bald eagles.

Under terms of its federal operating license for Bagnell Dam and the Osage Power Plant, Ameren Missouri operated a fish hatchery at the lake until 1997, when it signed an agreement with the Missouri Department of Conservation to conduct fish stocking there.

Supported by an $80,000 annual grant from Ameren Missouri, the fish stocking program has resulted in a greater diversity of species being stocked in the lake, than was possible with the small hatchery operation in the past.

As a result, the Osage River downstream from Bagnell Dam is one of the highest fishing and fish catch areas in Missouri, containing more than 80 species. Ameren Missouri has also worked with the Missouri Department of Conservation to enhance the fishery by raising dissolved oxygen levels during the hottest summer months.

For its dissolved oxygen enhancement and other programs to protect aquatic resources, the American Fisheries Society, the world's oldest and largest organization of fishery scientists, presented Ameren Missouri with its prestigious Citizens Award in 1998. Two years later, Ameren Missouri's Osage Plant was one of three hydroelectric projects honored by the National Hydropower Association for Outstanding Stewardship of America's Rivers.