Round Lake is a registered National Natural Landmark, where visitors can snowshoe or cross-country ski on miles of trails. Various wildlife make Green Lakes State Park their home and can best be observed from the hiking and ski trails.
The Green Lakes Bird Conservation Area is unique in that it contains significant tracts of both mature forest and grassland habitat, providing habitat for an unusually diverse suite of bird species. Grassland-breeding species include Eastern Meadowlark, Bobolink, and Grasshopper Sparrow. Mature forest birds include Rose-breasted Grosbeak, Eastern Wood-Pewee, and American Redstart.
More information on Green Lakes State Park can be found online.