The stream you just crossed is Walnut Creek. It was straightened by early settlers and this caused the erosion that is evident by how far the water has sunk below its banks. Along this streams, wildlife can be found in the cover of the trees. Beavers, skunks, muskrats, and opossums are a few animals that prefer the tree cover along waterways to the grasslands.
Each of these small animals play a part in the tallgrass prairie. A beaver dam will one day create a wet meadow, the skunks eat insects and help spread seeds, the muskrat helps clean away invasive plants and creates habitat for other animals, while the opossums are scavenging away for all the food they can find.