Kelly's Run, Lancaster County, PA

 Much of eastern North America consists of landforms characterized by steep sides and flat or rolling tops. The Allegheny Plateau is a particualrly large-scale example: a whole ocean's worth of seafloor sediments uplifted, but still mostly flat, and now dissected by streams. Even in our biggest Eastern mountains from Blue Ridge to the White Mountains, the steepest and most mountainous terrain is on the sides, more recent erosional surfaces, while closer to the top becomes broader and flatter. A hiker can climb steeply past cliffs and waterfalls only to reach hotels and campgrounds at the higher elevations.

A huge but subtle instance is the Piedmont. Hardly mountainous at all, it is underlain by metamorphic rock formed during mountain building at an earlier era of the earth's history. Although worn down, the bedrock is still erosion-resistant. The border between the coastal plain and the Piedmont is marked by the "fall-line" of industrial water power fame.

Looking at a section of the mid-Atlatic Piedmont in Southestern PA and MD, we we see that the land rises gradually from the coastal plain as you continue north, reaching five or six hundred feet above sea level before dropping off to a fertile Limestone valley around Lancaster and Harrisburg. The landscape here is mostly cornfields and pastures on gentle rolling hills. The Susquehanna River, on its route from Lancaster and Harrisburg's valley to the Chesapeake Bay, slices through the Piedmont, creating a gorge with some interesting terrain in the middle of a gentle fertile region: some sheer cliffs, and some steep-sided ravines where streams drain the sides.

The farmland is centuries old so imagine my surpriseto find old growth forest in the rocky ravine of Kelly's Run, as it descends to the Susquehanna.

In the heavily forested, thinly-settled Allegheny Plateau further up the Susquehanna, hundreds of steep, rugged ravines mostly were logged. It's hard to find many old trees outside of a few well-known and celebrated spots. Although not very intensively farmed, industrial logging around the turn of the 20th century reached nearly everywhere in this area.

In Lancaster County however, settlers in the 17th and 18th centuries, or their workers or slaves, probably cut the trees by hand during and hauled them away with oxen, to clear fields where forests had stood during Indian settlement. A steep ravine was probably not worth their blood sweat and tears. During PA's lumber boom, it may have just been too small and too far from other timber resources to be profitiable for lumber barrons.

I think this is a common story. Ironically the older, more thoroughly settled parts of the Eastern US probably have more old growth forest, in little bits and pieces, than the large areas of green that one can see on a map in between the Eastern Seaboard and the Midwest.

The forest along Kelly's Run is an exquisite combination of northern and southern species. Tulip poplar is probably the most common along the river and on the slopes, along with a really nice mix of oaks - red, white, black, chestnut and scarlet - and hickories more upslope. Some hemlocks and sweet birches attain decent size on shady steep slopes. Rhododendron creates a jungle, but it shares the spotlight with paw paw patches, spicebush (including one of the biggest specemins I've ever seen, right along the trail), witch hazel, maple leaf viburnum and mountain laurel.

Highly recommended.