The transition zone between the beech-maple forests of the eastern U.S. and the prairie and oak-hickory forests of the west occurs on the eastern edge of Illinois. American beech, sugar maple, and tulip trees are common species of the eastern forests. Beech trees are distinctive with their pearl-gray bark and their tendency to occur in clumps as new trees grow from the surface roots of older trees. A mature beech-maple forest is found in Robeson Hills Nature Preserve.

SIZE: 170,654 acres; 267 square miles

LOCATION: Eastern Illinois along the Indiana border; Clark, Crawford, Edgar, and Lawrence counties

The Upper Wabash River RRA encompasses the Wabash River mainstem from where it enters Illinois south to just above Lawrenceville, and the narrow band of small tributaries to the river. The Wabash River is wide and slow flowing with sand-gravel substrate in this area. This is one of the last relatively unaltered big rivers in the midwest.

LANDCOVER : This RRA is predominantly agricultural (63%), followed by wooded (22%). Moderate percentages of upland and bottomland woods occur in this site. Nonforested wetlands are not abundant.

NATURAL AREAS : A total of 2,212 acres comprise four Natural Areas. The largest is the 1,929 acre stretch of the Wabash River at Mount Carmel.

BIOLOGICALLY SIGNIFICANT STREAMS : A 76-mile stretch of the Wabash River is designated as a BSS stream in this RRA.

HERITAGE SITES : There are few Heritage sites in this RRA. One community type, one plant species, and four animal species are represented by the eight Heritage occurrences in this site.

STATE AND FEDERAL LAND : Part of Lincoln Trail State Park occurs in this RRA.

NATURE PRESERVES : Robeson Hills is the only Nature Preserve in this RRA. It is a remnant upland forest with a beech-maple community as its most significant feature.

NATURAL DIVISIONS : This RRA lies almost entirely within the Wabash Border Division.