One Horse Gap


One Horse Gap is located in the Shawnee National Forest just outside the town of Herod in southern Illinois. It is managed by the United States Forest Service and is known for a short loop trail known as "the gap trail", which is a narrow part of the trail in the bluffs that allows only one horse to pass through at a time. The trail provides access to Big Grand Pierre Creek, One Horse Gap Lake, War Bluff, and the River to River Trail. In addition to horseback riding, One Horse Gap also offers camping, disc golf, and rock climbing.

Geology and history

One Horse Gap is a unique geological area. During the Carboniferous period, local geological conditions laid down a thick bed of gray sandstone in what is now southern Illinois. The eroding sandstone rocks are the remains of mountains that are over 300 million years old. The area is geologically located on the south edge of an east-west trough formed by the northward tilt of the bedrock, and has been greatly affected by earthquakes and uplift. The combined effects of tremors, glacial melt waters, rain, freezing, thawing and wind have naturally sculpted the bluffs into several unusual formations. Unlike, much of Illinois, this plateau was never covered by glaciers; the furthest advance of ice sheets during the Illinoian glaciation stopped just north of the area. The area rock formations have been described as "reminding me of a moon scape." Large areas are rounded and bare of vegetation.
As with other wilderness areas within the Shawnee National Forest, One Horse Gap is made of second-growth forested areas, also known as a "Depression Forest," that until the land condemnations of the 1930s, was used as agriculture and logging land. Between 1880–1920s, Southern Illinois played a national role in timber production. The area was a logger's and lumber company's dream; individual acres of bottom land hardwoods yielded 25,000 board feet compared with an average bottom land forest of the state at 9,000 board fee. However, as a consequence of the reckless clearing, intensive logging, and the local practice of annually burning off the woods, southern Illinois hill-land was severely eroded or badly damaged by 1930. In the first year of operation, 1933–1934, the Civil Conservation Corps brought much needed jobs to the poverty stricken areas; a total of 40,888 acres in options was approved on 263 tracts at an estimated cost of $4.59 per acre. By 1939, the Forest had 183,446 acres purchased or optioned, and on September 6, President Roosevelt proclaimed the purchase units as the Shawnee National Forest.