National Natural Landmarks
Cottonwood Slough-Dry Run
Cottonwood Slough-Dry Run
Cottonwood Slough-Dry Run is a glaciated finger outlet of the world's largest Pleistocene glacial lake. The site contains a completely undisturbed wetland complex including potholes, streams, shallow open water, lakes, and marsh.
Location: Roberts County, SD
Year designated: 1975
Acres: 6,424
Ownership: State, Private
← Back to listing of all states and territories.
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.