Mentor Marsh has been designated by a National Park Service as the National Natural Landmark since 1965 for being one of the most species-rich sites on the Great Lakes shoreline. It was named Ohio’s first State Nature Preserve in 1971. This unique wetland suffered dramatically in the late 1960s when salt-mine tailings leached into Blackbrook Creek. By the early 1970s, most of the swamp forest trees and marsh plants had died. The site was overtaken by common reed (Phragmites australis), a 14-foot-tall non-native invasive plant. Phragmites grew so densely within the nearly 4-mile-long marsh basin that an estimated 1 billion plants were growing just a few inches apart. After partial abatement of the salt source, the Cleveland Museum of Natural History began a large-scale restoration of Mentor Marsh in 2012. Under the guidance of Museum restoration ecologists, the Phragmites is being treated via helicopter and a ground-based amphibious vehicles. The Phragmites has also been physically mashed to allow native plants to grow. The results thus far have been heartening. Dozens of native plant species are sprouting throughout the Marsh and rare marsh birds — such as American and Least Bitterns, Virginia, King and Sora Rails,Gallinules and Snipe, are now nesting. The restoration has created stopover habitat for waterbirds and waterfowl, and fish such as Northern Pike are spawning and Yellow Perch fingerlings are starting to use the marsh as a nursery.