The Mima Mounds area is a prairie containing unusual soil pimples of black silt-gravel. The mounds range in height from barely perceptible to a maximum of seven feet.
Year designated: 1966
Please remember, National Natural Landmarks (NNLs) are not national parks. NNLs are owned by a variety of public and private entities and allowing visitation is at their discretion. Many NNL sites maintain public websites where additional information may be found.