Driving west from Columbus on State Route 161, the pancake-flat fields of Union County began to undulate slightly as my wife Karen and I approached Champaign County. By the time we reached the county line, the road dipped and climbed and soon there were hills and valleys.
The same ice sheet responsible for leveling Union County created Champaign County?s ridges, which are moraines of gravel and stone transported from Canada and then deposited as the glaciers retreated northward.
We were traveling on a pleasant Sunday afternoon in mid-March to Cedar Bog Nature Preserve about 55 miles west of Columbus and just south of the Champaign County seat of Urbana. Acquired by the state in 1942, Cedar Bog is owned by the Ohio Historical Society. The preserve now includes 427 acres.
Site manager Terry Jaworski gave us a guided tour, as he does for many visitors, including school classes and scout troops. He is a tall, affable man who for 28 years has collected and readily shares the stories of the natural and human history of the preserve.
Early in our tour, Jaworski noted that Cedar Bog is a misnomer. The preserve is actually a fen, which is a wetland fed by springs, rather than a bog, which is an ancient pond that has gradually been filled by sphagnum moss. A bog gets clogged and a fen gets flushed, according to an old adage.
The preserve is on top of an ancient river valley more than four miles wide and 28 miles long and filled with glacial till. Rain water filters through the moraine with its concentration of limestone and rises to the surface in Cedar Bog. Unlike the trapped, acidic water of a bog, the springs are pH neutral and feed the east branch of Cedar Run. The cool water has maintained the climatic conditions that permit northern species to survive since the glaciers melted.
?As a natural area, Cedar Bog has always been recognized as special,? Jaworski said, citing signs of human habitation back to the archaic Indians. He speculated that humans have been attracted to the fen over the centuries as a source of medicinal plants not found elsewhere.
We sat on a wooden bench along the mile-long boardwalk and looked across the sedge meadow, not yet green, bounded by northern white cedar trees, for which the preserve is named. What Jaworski described as ?the great amphibian chorus? had already opened for the season. Western chorus frogs, which had wintered-over in the fen, serenaded us. The song of these small frogs is the trill of a finger run across the teeth of a comb. The frogs? call is repeated over and over again from one side of the meadow, then the other ? blending like, yes, a chorus.
Beneath the cedar trees, large patches of skunk cabbage sprouted and hepatica, a ground cover, bloomed with tiny white flowers. Jaworski pointed to the moist black earth just off the boardwalk where the queen lady slipper orchid, the largest orchid native to Ohio, and the green woodland orchid would delight visitors later in the summer. He also singled out the dwarf birch trees, now native to the Arctic Circle, and last year?s dried frond from the maiden hair fern, also a native of Canada.
?This was Ohio at the end of the Ice Age,? he said as he concluded his natural history lesson with his head cocked as if he were listening for a mastodon to step into the sedge meadow.
Cedar Bog is four miles south of Urbana off U.S. Route 68 on Woodburn Road. The preserve is open April through September on Wednesday through Sunday from 9 a.m. to 4:30 p.m. and by appointment for the rest of the year.
Admission is free to members of the Ohio Historical Society. For other visitors, adults are $4, children six to 12 are $1.25, and children five and under are free. To inquire about a tour, call toll-free at (800) 860-0147.