Big Walnut Creek - A National Natural Landmark

That the Big Walnut Creek Valley is a natural wonder is evidenced by the fact that the U.S. Park Service designated 502 acres of it a National Natural Landmark (NNL) nearly a half century ago. By its 1968 designation, that means Big Walnut contains "outstanding biological and geological resources."

"The site contains one of the few stands in Indiana where beech, sugar maple, and tulip poplar grow on alluvial Genesee soil and includes relict species of a postglacial forest that occupied the area 5,000 to 6,000 years ago," the Park Service says.

And the recognition doesn't end there. Last Wednesday, I hiked through two Dedicated State Nature Preserves -- Big Walnut/Tall Timbers Trail Unit and Hall Woods -- and alongside a bean field to find a third -- the Hemlock Ridge Nature Preserve -- too overgrown to negotiate. The three are located along a six-mile stretch of the Big Walnut on either side of Bainbridge, a one-light town west of Danville with a population smaller than its zip code, 736 and 765.

Among the natural wonders at Big Walnut are the largest known hemlock trees in Indiana. But, as I would learn during and after my hike, they are visible only from the water and not from the Tall Timbers Trail, a 1.9-mile loop that traverses a dramatic ridge with majestic ravines with a spur to the creek. The trail passes through Fortune Woods, a 120-acre stand of old-growth hardwoods.

The 2,697-acre Big Walnut Nature Preserve is owned by The Nature Conservancy and co-managed with the Indiana Department of Natural Resources Division of Nature Preserves.

The 94-acre Hall Woods, owned by DNR Nature Preserves and also part of the Big Walnut NNL, likewise borders the creek and features a loop trail through the moist, upland and bottomland forests with stunning ravines and creekside sights and sounds.

After failing to see any evergreens at Big Walnut, I figured I couldn't miss them at Hemlock Ridge, a 39-acre Central Indiana Land Trust site with "a stand of hemlock with views overlooking Big Walnut Creek," according to Nature Preserves.

But the trail enters the preserve through a meadow that was so overgrown that the path disappeared. I simply wasn't willing to risk biting-bug exposure walking through waist-to-armpit-high vegetation -- mostly goldenrod -- on a high-80s day in mid-September.

I'm not sure I'll be back in that part of the country anytime soon, but if I am, it'll be in the spring.

Photographs: Top, Big Walnut Preserve; Left, Hemlock Ridge Nature Preserve; Bottom, Hall Woods Nature Preserve