Derald W. Dinesen Prairie is a 20-acre remnant of native tallgrass prairie. It is located six miles northeast of Harlan in northeastern Shelby County. Derald Dinesen purchased the area in 1943, realizing that the Iowa prairie was nearly a thing of the past. It was dedicated in 1977 as a biological state preserve. He told reporters at the dedication, “I guess the reason I set aside the land was based on instinct. The instinct to leave something behind for posterity of what you believe in. I just wanted to see and have others see the beauty of the land as it existed years ago when the Indians roamed [the land].” Derald Dinesen’s gravestone can be seen on the top of the hill and from this vantage point a wonderful overlook of the preserve can be seen. Two stone benches in the parking area are placed in memorial of Dean L. Frederickson, a prairie advocate from the area. In 1983, the preserve came under control of the Shelby County Conservation Board.

The gently rolling native prairie, with its loess-topped ridges typical of the western portion of the Southern Iowa Drift Plain, was formerly hayed every fall. A ridge crosses the preserve from west to east with a gradual drainage eastward to the wide valley of the Nishnabotna River. It is covered with waist-high prairie grasses. Porcupine grass and prairie horsetail are seen here, along with Junegrass, sideoats grama, Indian grass, and Canada wild rye. Forbs are abundant and showy during the growing season, with at least 114 species of plants. In the spring, beautiful swells of prairie phlox, indigo bush, hoary puccoon, blue-eyed grass, lousewort, and bird’s-foot violet wave across the prairie, followed by the summer flowers of Canada anemone, rattlesnake master, prairie turnip, prairie coreopsis, leadplant, New Jersey tea, compass plant, and gayfeather. Fall’s flora includes several asters, blazing star, Maximillian sunflower, and stiff goldenrod.

The prairie is excellent habitat for prairie species of birds such as bobolink, dickcissel, meadowlarks, vesper sparrow, and upland sandpiper. Many small mammals inhabit this prairie. Some of the more common ones include prairie vole, meadow vole, thirteen-lined ground squirrel, whitetailed jackrabbit, and eastern cottontail.