Poplar Bluff and Stephen J. Sun conservation areas are located in Butler County, two miles east of Poplar Bluff on U.S. Business 60, then 3.50 miles north on Route NN. Turn left on County Road 544 and follow it one mile west to the area parking lot. These two conservation areas comprise 1,637 acres in five tracts and include six-acre Carpenter Lake and the 80-acre Poplar Bluff Forest Natural Area. The University of Missouri acquired what is now Poplar Bluff Conservation Area under the Agriculture College Act of 1862. The Conservation Department purchased this 912-acre tract from the University in 1965. An additional 240 acres was purchased in 1995.
Stephen J. Sun Conservation Area consists of 485 acres. The Department acquired parts of this conservation area in 1988, thanks to a donation by the Sun family. Department funds were used to purchase the remainder of the lands.
These two conservation areas represent a unique contact zone of two major ecosystems- the Ozark highland and the coastal plain wetland. The hills of Poplar Bluff Conservation Area have soils of primarily Clarksville or Loring silt loams. The soils covering the fields of Stephen J. Sun Conservation Area are mainly Elk, Adler, and Calhoun silt loams. Upland tree species include hickory and black, white, and scarlet oak. Cherrybark oak, sweetgum, red maple, and sugarberry are the primary bottomland species.
Several endangered species and unusual plants inhabit both areas. On Stephen J. Sun Conservation Area both river otter and swamp rabbits have been observed. The Poplar Bluff Forest Natural Area provides an opportunity to experience a high quality bottomland forest with many large trees.
Carpenter Lake is an old oxbow lake, located at the contact zone between the Ozarks and the Mississippi lowlands.