Round Lake, located within Green Lakes State Park, is one of 11 meromictic lakes reported in the United States. The site also contains about 20 acres of outstanding virgin mesophytic forest adjoining the lake.
Year designated: 1973
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.