Backpack Trail Guide

Trails / Illinois / Shawnee National Forest

One Horse Gap Loop

Shawnee National Forest, North Benham Ridge area (near Herod, Pope County)

One Horse Gap is named for a passage through a sandstone bluff that Wikipedia says is “only wide enough for one horse to pass through at a time.” It sits in the hills near Herod in Pope County, on the River to River Trail between Garden of the Gods and Lusk Creek. The River to River Trail Society suggests a loop of about 20 miles from the Benham Ridge trailhead, ideal for a two- to three-day weekend.

It’s horse country. The trails get heavy equestrian use, so expect mud in places.

The hike

Wikipedia describes the area’s sandstone as dating to the Carboniferous period, about 300 million years old, and notes that this part of Illinois escaped glaciation. The bluffs were shaped by “tremors, glacial melt waters, rain, freezing, thawing and wind.” The land was heavily logged until the 1930s and became part of the Shawnee National Forest in 1939.

The short Gap Trail loops through the namesake passage, and Wikipedia says it gives access to Big Grand Pierre Creek, War Bluff, and the River to River Trail. One Horse Gap Lake is reachable on the trail system.

The Benham Ridge trailhead is fairly new. American Trails says it was built with Recreational Trails Program funding between 2014 and 2018, in a partnership between the Shawnee Trail Conservancy and the Forest Service, and placed to avoid private land where changing ownership threatened public access. The same project relocated 5.4 miles of trail along Big Grand Pierre Creek from an eroding user-made route to an engineered sidehill line to cut siltation. American Trails notes the trailhead serves both equestrians and backpackers on the River to River Trail.

The River to River Trail Society recommends hiking its loop from the Benham Ridge trailhead. In a trip report posted on the Lemmy forum, a hiker who goes by ffmike followed that loop “mostly,” adding a few side loops for about 28 miles over a day and a half. He found some trails “not much used and overgrown,” balanced by many user trails not on the map, and said the area “gets heavy horse traffic,” with a few muddy stretches. He also warned that “the whole area is overrun with poison ivy” and that “the ticks are out in force,” and noted that waterfalls and cascades were mostly dry.

The River to River Trail Society also runs group day hikes here; its October 2018 outing was a figure-eight of about 4 miles plus 2.25 miles in the North Benham Ridge area, rated moderate with hill climbs.

For the next wilderness west on the River to River Trail, see the Lusk Creek Loop; to the east is the Garden of the Gods loop.

Tips

Camping

The Shawnee doesn’t require permits for dispersed camping. The Forest Service’s occupancy order limits stays to 14 days in a 28-day period and bans camping within a quarter mile of developed campgrounds or picnic areas. Its 2023 recreation guide says primitive camping isn’t allowed within 150 feet of water or in natural areas, and that no stream water meets drinking standards. Forest order 09-08-25-03 keeps horses on designated trails in the Big Grand Pierre Creek watershed. Follow Leave No Trace and pack out trash.

Inside Intel: ffmike camped beside One Horse Gap Lake and called it “a very nice spot,” with a catch: an access road reaches the lake, which “means there is far too much trash strewn around,” and motorcyclists showed up late at night. If you want quiet, a camp away from the road may suit better. Stay 150 feet from the shoreline.

Trail facts

The Lowdown

Muddy horse trails near One Horse Gap:

Heavy horse traffic leaves muddy stretches on these Shawnee trails. Before you buy a rain shell, see whether the Arc'teryx Beta SL is worth more than two cheaper options.

Is the Beta SL worth it? →

Where this comes from

This page draws on the sources below, along with other guides and trip reports. Links go to the original pages.

Before you go: This page is based on published trail guides, trip reports, and reviews, along with official park and agency information where we could find it. It’s meant to help backpackers discover new trails, not to replace current, official information. Conditions, closures, permits, campsites, and water sources change, and some details here may be out of date or wrong. Confirm everything with the managing agency and check current conditions before you head out, and don’t rely on this page alone for safety or navigation. Backcountry travel involves risk.