Hartwick Pines State Park preserves a forty-nine acre old growth forest dominated by towering three hundred fifty year-old white pine trees and also reflects the area's logging history through stump fields left by timber cutting, logging camp sites excavated by archaeologists, and a museum built in 1934-35 by the Civilian Conservation Corps with exhibits including a bunkhouse, mess hall, company store, and blacksmith shop. The Salling-Hanson Company of Grayling logged most of the area between 1883 and 1925 and built logging camps where needed. A Memorial Building constructed in 1929 from logs brought from the Lovells area was built under Karen Hartwick's direction as a memorial to her husband Edward and later served as the park's visitor center for more than sixty years. From 1933 until 1942, the Civilian Conservation Corps operated a camp in the park and built many trails, bridges, museum buildings, and a campground, planted hundreds of thousands of trees, and cut fire breaks. The park also features annual Wood Shaving Days and Black Iron Days festivals, when visitors can explore the old growth pine forest, see a steam powered sawmill, and enjoy demonstrations by whittlers, blacksmiths, woodcarvers, artists, and others. The Enterprise Mill dates to 1940, the steam traction engine is a 1912 Port Huron, and the sawmill operates during the park's summer festivals. White pine, hemlock, and red pine are identified by their distinctive needles and cones, and the park and its surroundings provide high quality bear habitat, as shown by a black bear nicknamed Karren, a long-studied Michigan DNR research subject known to spend much of her time in and around the park.