Spread Eagle Barrens protects an extensive landscape of bracken grassland and barrens dominated by scattered jack pine, red pine, scrub oak, and quaking aspen. The sandy soils support an understory of sedges, bracken and sweet fern, slender wheat grass, muhly grass, poverty oats, hazelnut, serviceberry, blueberry, and willows. A mosaic of six different communities, the natural area was established to protect the Pine Barrens community and associated flora and fauna that require large expanses of open vegetation. Frost pockets, treeless depressions where frost may occur at any time of year, punctuate the landscape. Sedges, lichens, and other plant species have adapted to this harsh microclimate and are able to dominate these low-lying areas. In contrast, bracken fern, Jack pines and other small trees dominate the uplands where they are interspersed with grasses. Many rare or declining species of large open landscapes live here. Birds include northern raven, winter wren, eastern bluebird, warbling vireo, Nashville, chestnut-sided, pine, and mourning warblers, clay-colored sparrow, common nighthawk, eastern towhee, and Brewer's blackbird. Mammals include black bear, fisher, badger, coyote, red fox, and white-tailed deer. The lower reaches of the Pine River, a designated Wild River, traverse the site and the Menominee River forms the property’s eastern boundary. Management activities such as timber harvest and prescribed burning help maintain the open landscape. Spread Eagle Barrens is owned by the DNR and WE Energies and was designated a State Natural Area in 1995.