14 April: We biked from Vienna to Tunnel Hill and back on the Tunnel Hill State Trail. This 9.3-mile segment of the over-50-mile-long rail trail has an excellent crushed stone surface and climbs gently through forest and farmland from Vienna to the trail’s namesake tunnel at its highest point. The tunnel was just long enough to be too dark to see the tunnel walls in the middle even though we could clearly see daylight at both ends (a little spooky!). Spring wildflowers lined the trail for much of our way and the trail passed by some scenic rocky outcrops. The original railroad that the trail follows was founded in 1872 by Civil War general Ambrose Burnside. More recently, the owners of the line had refurbished the tracks in anticipation of a freight contract, but they lost the bid to another rail line and eventually donated ownership to the state of Illinois, which developed the bike trail.
People we met and talked with in campgrounds, on the bike trail, and at visitor centers have most friendly and informative. In the afternoon we stopped at the wetlands center at the Cache River State Natural Area, where there are excellent historical and ecological displays about the local area. The southern tip of Illinois has several state champion trees, and at least one national champ. We went to view the state champion water tupelo gum tree, the state champion cherrybark oak tree, and a couple of very big and old baldcypress trees (the state champion baldcypress is also nearby but not readily accessible up close). Hiking the Heron Pond Trail, Paul was startled by rustling leaves near his feet and looked down to see a very big water moccasin (a little close for comfort!). The hike led to a boardwalk deep into a baldcypress swamp, with interpretive signs. Baldcypress are very long-lived trees, most closely related to sequoias and redwoods, but they are similar to larches in that they drop their needles each fall. The water in the swamp was very still and carpeted with the tiny leaves of the aquatic plant duckweed, except for a few squiggly traces left by swimming frogs and snakes. 
Very cool!