Southern Illinois' Tunnel Hill State Trail is a gem of a route, with 23 trestle bridges (including one that is 450 feet long), several ghost towns, a beautiful park, a comfortable trailhead in Vienna Station and, of course, its namesake tunnel—an impressive corridor that once measured 800-feet-long until a collapse in 1929 shortened it by some 300 feet. The first railroad tracks laid on this corridor caused such a stir that in 1870, local farmers, anticipating shipment-ready crops, planted orchards even before the line's tunnel was complete. In 1991 the original corridor of 47.5 miles was donated to the state, and just 10 years later, it was opened to the public as a multiuse trail.
Begin at the Barkhausen Wetlands Center, which serves up instant trailside gratification within the first 2.5 miles, already showcasing a bridge and scenic overlook before even reaching the town of Karnak (restrooms, drinking fountain, and ample parking). A few miles farther in you will come to the "ghost town" of Forman (to your left) that hints at a scary movie set from a Hollywood backlot.
The scenic trail passes more bridges, as you make your way to the town of Vienna Station. There is a nice park here that provides an ideal rest and picnic spot, especially if you have children along. Leaving Vienna Station, head toward Tunnel Hill and the trail's midpoint. In the 9 miles between Vienna Station and Tunnel Hill, there are four more bridges before the landmark tunnel. It's handy to use a flashlight as you travel through the cavernous, 543-foot tunnel. If you're on bike, you may want to dismount and walk it through. Be especially careful of other trail users coming in the opposite direction.
After Tunnel Hill—the highest point on the trail—there is a gentle 2-percent grade downhill for the remaining 25 miles to Harrisburg. Soon after leaving the Tunnel Hill trailhead, you'll travel through the Shawnee National Forest, a stunning landscape with a high tree canopy that shades a trickling brook on the right. You're more likely to hear the birds here than you are to see them, but the local rabbit population is everywhere. The journey here is amazingly quiet and rural.
After 6 miles you arrive in the town of New Burnside, which takes its name from Civil War General Ambrose Burnside, a founder of the original railroad. The terrain here is marked by looming bluffs, providing a dramatic contrast to the forest you traveled through earlier. Another 4.4 miles of travel takes you out of the forest and into a very flat section along US 45 to Stonefort, whose trailhead includes a well-restored railroad depot.
The next 6.7-mile stretch remains within sight of US 45 most of the way to Carrier Mills. Keep an eye out for turtles and snakes, which also like to use this trail. After Carrier Mills, the last 7.5 miles of trail into Harrisburg meander past farm fields and neighborhoods. The route in Harrisburg becomes a mix of crushed stone and concrete, ending at the trailhead on the north side of town.
From there, the trail crosses State Route 13 and the Saline River bridge at Muddy, continuing another 8.1 miles from Harrisburg through flat farmlands, all the way to Eldorado. Although seamless, this newest connection between Harrisburg and Eldorado is not managed by the state’s DNR. In Eldorado, the trail intersects another beautiful and popular rail-trail, the Eldorado Bicycle and Walking Path.
To access the Barkhausen Wetlands Center near Cypress, take Interstate 57 Exit 30 to State Route 146 and proceed east for 9.6 miles. Turn right on State Route 37 and continue for 8.8 miles. Pass through the town of Cypress and look for the wetlands center on the left.
To reach the trailhead at Tunnel Hill, take I-24 Exit 14 to US 45 and head north for 5.8 miles. Turn left on Tunnel Hill Road, continue for 1.0 mile, and look for the trailhead on the right, just before Possum Rd/Main St.
To reach the Harrisburg trailhead from Interstate 57 Exit 54, take State Route 13 east 24.2 miles. Turn right on US 45/N Commercial St and head south for just 0.1 mile. Turn right on Walnut Street then right on Veterans Drive. The trailhead is on the right.