Cowles Bog is an 8,000-year-old fen in the Indiana Dunes National Lakeshore, near Chesterton, Indiana. It is named for Dr. Henry Chandler Cowles who did his pioneering work in ecology and ecological succession here. His work brought international attention to the area which led to efforts to preserve the Indiana Dunes. It was designated a National Natural Landmark in 1965.PreservationDr Cowles had been writing papers on plant succession for several years based on research he did in the area before he was part of the 1913 International Phytogeographical Excursion which brought other international scientists to the site. Dorothy Buell founded the Save the Dunes Council which led to the purchase of the bog.LocationThe bog is located west of Mineral Springs Road. The general area is accessible by the Cowles Bog Trail of the Indiana Dunes National Lakeshore. Parking is available at the trailhead, just before the guardhouse to Dune Acres. The trail does not lead into the bog, which is nearly inaccessible due to the nature of the plant life surrounding it. Dr. Cowles work included the bog and the marshlands to the south of the trail and the dune slopes to the north of the trail. Cowles Bog is drained by the West Branch Tributary of Dunes Creek to Lake Michigan.