National Natural Landmarks by state


Dewey's Pasture and Smith's Slough
Dewey's Pasture and Smith's Slough, a National Natural Landmark in Iowa.

There are seven National Natural Landmark sites located within the state of Iowa. Natural features represented include large glacial pothole lakes, remnant prairie, an expansive loess (wind-blown sand) landscape, and highly decorated caves. All seven sites received NNL designation between 1965 and 1987. Sites range in size from 120 acres to almost 700 acres and are owned by various landowners including the Iowa Department of Natural Resources and private individuals.

Below is a map of sites in Iowa.

National Natural Landmark sites are located in the following counties: Clay, Dickinson, Dubuque, Hamilton, Harrison, Howard, Monona, Palo Alto, and Winneshiek.

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Iowa state map White Pine Hollow Preserve Anderson Goose Lake Loess Hills Dewey's Pasture and Smith's Slough Hayden Prairie Cayler Prairie Cold Water Cave

Please remember, National Natural Landmarks (NNLs) are not national parks. NNL status does not indicate public ownership, and many sites are not open for visitation.

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