The Mingo Wilderness occupies 7,730 acres on the western half of the Mingo National Wildlife Refuge in southeastern Missouri. Terrain is marshy flatlands, surrounded by low hills. The MING1 IMPROVE site is located ~3 km northeast of the town Puxico near the southeastern corned of the Wildlife Refuge. The site elevation is 112 m (367 ft). Surrounding terrain is hilly and groundcover is predominantly forest and lakes.