Spitler Woods State Natural Area is a 202.5-acre protected woodland beside Mount Zion in the Decatur area of central Illinois. Managed by the Illinois Department of Natural Resources, it includes an Illinois Nature Preserve covering the eastern two-thirds of the property, where an old-growth grove of white oak and hickory survives as a remnant of the region’s former hardwood forests. Named for Ida B. Spitler, who donated the woods to the state in 1937, the area also contains two trails totaling 2.5 miles along Squirrel Creek. Its mature trees, diverse understory, wildlife, and accessible setting make it an important example of old-growth woodland near an urban area.