Walking on a Pennsylvania trail. Photo by D. Sillman
(Click here to listen to a audio version of this blog!)
We left Apollo in the early afternoon and drove west in bright sunshine. The air was as warm and humid as you would expect for Western Pennsylvania in late July. It had rained overnight, but all of the pavement and any lingering puddles had thoroughly dried. In a few hours the sun dropped low enough in the sky to glare up the windshield and our sunglasses. We had to flip down the sun visors and watch the road ahead of us through a narrow, horizontal slit between the visor’s edge and the dashboard. Driving west in the late afternoon is tough.
The topography of Western Pennsylvania is rolling and curvy. Long ridges run, in general from the SW to the NE reflecting the pattern of the nearby Chestnut Ridge and Laurel Hill. This is the western edge of the Allegheny Mountains which in turn is the western section of the Appalachian Mountain Range. The Appalachians are ancient mountains, hundreds of millions of years old. They are well worn and fragmented by weathering and erosion. In between the ridges are rills, and creeks and rivers of varying sizes and energies. The flowing water adds more complexity to the landscape. It has been said that here in Western Pennsylvania there are no hills, only valleys!
You feel this topography when you drive on all of the area roads. There are almost no straight lines from any point A to any point B. Short, straight line map distances often require long arcs and, sometimes, opposite directional hypotenuses to be accomplished. It took us 45 minutes of zigging and zagging to get to the Turnpike entrance and really start our journey west!
The Kiski River and surrounding ridges. Photo by D. Sillman
All of the ridges and valleys here are lush and green and well covered with trees. This was the middle of the great eastern hardwood forest of pre-colonial North America. Most of those trees (the oaks, the chestnuts, the sugar maples, the white pines and, further north and down in many nearby, cool valleys, the hemlocks) were clear cut in the late 19th and early 20th Centuries, or, in the case of the chestnuts, killed by an invasive fungus. They were replaced so rapidly and so efficiently by a hodgepodge of hardy, fast growing hardwood species (like red maple, white ash and black cherry) that it looks like the great eastern forest is still here. The diversity and array of trees we see today, though, are the product of human interference. These forests have never existed on Earth before! Their persistence and sustainability are not known.
The altitude of Pittsburgh is expressed in most references as a broad range. The city, and much of Western Pennsylvania, is between 710 and 1370 feet above sea level. This range, of course, reflects the topographic complexity of the ridge and valley terrain. So many interesting microclimates and microhabitats are generated here! So many wonderful places to hike and explore!
Photo by D. Sillman
Driving west we get to Ohio in about an hour. The eastern-most parts of Ohio look like Western Pennsylvania: rolling, stream bisected, often forested terrain, but soon we drive out of the ridge and valley topography into at first a rolling and then an increasingly flattened plane. Looking at a road map (which is a rare thing, I know, in these days of I-Phones and audio-based direction systems, but I don’t feel right unless I have my Rand McNally road atlas with me in the car!) you see the sudden change in the nature of the surrounding highway grid. Interstates and local roads run increasingly due north and south or due east and west making a neat, endlessly repeating geometric pattern of squares and rectangles.
Ohio was also part of the pre-colonization hardwood forest. One of my agronomy professors at Ohio State talked about the cutting and clearing of all of trees to make space for agricultural fields. There were so many trees felled that the downed wood could not be used! It was, instead, just burned in place. Great piles of trunks and branch wood were set on fire generating mountains and mountains of ash. The ash eventually washed into the surrounding creeks and rivers turning the water gray. Surface water pollution in the United States has a very long history!
Photo by D. Sillman
Looking out the window of the car as we race across the geometric grid of Ohio we see occasional stands of trees (the same fast growing species that dominated Western Pennsylvania), but mostly we see open fields in which hay has been recently cut and baled or in which dense stands of corn or soybeans are planted. The great Ohio forest has become open farmland.
We are going steadily up. The altitude of Columbus, Ohio is 902 feet above sea level. The precision of a single number for this average altitude reflects the leveling of the topographic landscape. There are hills, but they are low and rolling.
Photo by D. Sillman
The next state is Indiana. The square, north-south and east-west grid of roads continues. Indiana was the western edge of the pre-colonization, eastern hardwood forest. It was also vigorously cleared for agriculture. Expansive fields of corn, soybeans, and hay dominate the roadsides. Indianapolis sits at 900 feet above sea level, almost the same altitude as Columbus, so we have been driving along a steady, flat plane.
Water towers have become more and more prominent across the landscape. Each is labeled with the name of their town. You see the scattered pattern of towns stretching out toward the increasingly horizontal horizon line. The towers are a symptom of the flatness of the terrain. They enable municipal water systems to pump water into their elevated tanks and then use gravity (free energy!!) to maintain delivery pressure in the water mains. Back in Pennsylvania there were more water tanks than towers. The tanks were located on high hills in the middle of water-main grids. There was a tank very close to my old house in Apollo that was filled by pumped water from the pressurized water mains.
The rest stops in Indiana are densely wooded and shady. The trees are different that the fast growing array we had seen in Pennsylvania and Ohio. Chestnut oaks, northern red oaks and basswood trees dominate the “rest stop forests.” The wind was also much more intense. It blew hard and consistently all across Indiana, Illinois, Iowa and beyond! I remember being out on my Uncle Harold’s farm in northwest Iowa in late May twenty years ago, seeing extensive fields of three inch tall corn all of which were laying down across the soil surface because of the wind. I didn’t remember the wind from my childhood visits to Iowa, but was assured by my cousins that the wind always blew in Iowa.
We are driving out from under the extensive cloud cover that is generated at least in part by the proximity of the Great Lakes. Pittsburgh is one of the least sunny cities in the United States. It has, on average, only 59 clear days a year and 103 partly cloudy days (so, 162 “sunny days”). Pittsburgh has 203 days that are densely cloudy! On average, cities in the United States have 205 “sunny days,” and northern Colorado (our destination”) has 244 “sunny days” each year. Pittsburgh gets 38 inches of rain each year while Columbus gets 56 inches and Indianapolis, 42 inches. Our destination in northern Colorado gets 14 inches of rain each year. We are driving from the cloudy, wet forests of the east to the sunny, dry grasslands and mountains of Colorado.
On to Illinois, Iowa, Nebraska and Colorado!
(More next week!)
Enjoying your journey!!!
ML