Engelmann Woods Natural Area is a 149-acre protected reserve in northeastern Franklin County, Missouri, above the Missouri River near St. Albans. It preserves one of Missouri’s last remaining tracts of old-growth forest, making it an important remnant of the region’s earlier woodland landscape. Some trees are about 3 feet in diameter, 100 feet tall, and roughly 200 years old. The land was donated to the Missouri Botanical Garden in 1942, chiefly by Mrs. Oscar Johnson, later acquired by the Missouri Department of Conservation in the 1980s, and officially designated a natural area in 1983. A 1.5-mile hiking trail runs through the reserve.