Big Oak Tree State Park in East Prairie, Missouri, is a 1,029-acre state park and nature preserve created in 1938 to protect a rare remnant of bottomland forest within a broad landscape of drained cropland. It is especially significant for its wet-mesic bottomland hardwood forest, an unusual survivor in the Mississippi Alluvial Plain of the Gulf Coastal Plain, and for trees that have been recognized as Missouri or national champions as the largest known examples of their species. In May 1986, the park was designated a National Natural Landmark, and today it pairs preservation with low-impact recreation through hiking trails, an accessible boardwalk, an interpretive center, and picnic facilities.