Remembering the Pittsburgh Seam of Coal

From the Golden Gate Bridge to the Empire State Building, modern America started with the Pittsburgh seam of coal.

One of my earliest memories is staring out the passenger side window of my dad’s car as he taught me about the Pittsburgh seam of coal. Whenever we drove through a deep road cut—where the highway department had blasted through a hillside to lay the pavement—he would point out a distinct, thick black stripe sandwiched between layers of gray shale and sandstone. We’d be driving hours away from home, crossing state lines, and suddenly, there it was again. My dad would point it out in Maryland, spot it out in Ohio, trace it through West Virginia, and of course, catch it all over western Pennsylvania. He was an attorney whose practice focused on natural resources, and his dad was a mining engineer.

As a kid, it blew my mind that this single, continuous sheet of ancient, compressed swamp stretched across different states. It ties the whole region together underground. It was a massive, silent giant sleeping beneath our feet. Once I knew what to look for, I saw it everywhere. Today, the seam outcrops less than 1/2 mile from my house in Pittsburgh’s South Hills. Recently, I spotted it behind some buildings at the intersection of Painters Run and Bower Hill roads.

The engine of an empire

You can see it all over the Pittsburgh area, but most people today don’t know what the Pittsburgh seam of coal is, or why it was so important to the Pittsburgh region. Without the Pittsburgh seam of coal, people would not know Pittsburgh as the Steel City. Much of modern America started with the Pittsburgh seam of coal.

The Pittsburgh seam was one of the thickest, most widespread, and most easily accessible coal beds in the world. The U.S. Geological Survey (USGS) notes that the Pittsburgh coal bed runs over 11,000 square miles across 53 counties in Pennsylvania, West Virginia, Ohio, and Maryland. When early industrialists realized what they had sitting right under the hillsides, it set off an economic explosion.

The wealth pulled from this seam built the skyscrapers downtown, funded the massive Carnegie libraries and museums, and brought waves of immigrants to the region to work the mines and the mills. Yet, if you stop someone on the street today and ask them about the seam, you’ll likely get a blank stare. The physical evidence hides mostly underground. What remains is a modern region that has largely moved past its early history.

Coke is it

The Penn State Fayette Coal and Coke Museum documents how the chemical and physical characteristics of the Pittsburgh seam made it the worldwide standard for metallurgical coking coal. To understand why this specific coal was so valuable, you must understand coke. Most people think of the soda, but in the industrial world, coke gave us the Industrial Revolution. You can’t just throw coal into a blast furnace with iron ore to make iron and steel. Coal has too many impurities, like sulfur, which will ruin the final metal.

To solve this, industrialists baked the coal in massive ovens without letting it catch fire. This process burns off those impurities and leaves behind a lightweight, porous chunk of nearly pure carbon. That’s coke. It burns incredibly hot and clean, which is exactly what you need to smelt iron ore. As it turned out, the coal from the Pittsburgh seam was arguably the best metallurgical coal on the planet for making coke. It had the perfect chemical makeup. Because of this, the region mined the Pittsburgh seam to produce a massive amount of steel.

Built on baking coal

The demand for coke was so intense that entire communities sprang up all over the tri-state region just to keep the ovens burning. One of them is Cokeburg, a small borough in Washington County where I own a house today.

Cokeburg didn’t get its name by accident. It is a literal monument to the process of baking Pittsburgh coal. The official website for the Borough of Cokeburg notes that a coal company developed the town in 1900 as a coal mining settlement (initially called Shaft Four). They built it around the coking operations of the James W. Ellsworth Coal Co., part of Bethlehem Steel. The coke ovens gave the town its permanent name.

In the early 20th century, the glow from the beehive ovens ran day and night. The air was thick with the smell of sulfur, and the night sky would glow with a constant orange light. Cokeburg is a quiet town now, but its name carries the heavy, industrial history of the entire region.

The family legacy

My connection to the Pittsburgh seam was in my blood. While I never worked the mines myself, my grandfather lived and breathed the industry as a superintendent of the Georgetown No. 4 mine, part of Hanna Coal Co. and now owned by Consol Energy, out in Cadiz, Harrison County, Ohio. This area sits on the western edge of the seam’s massive footprint.

Hearing about his work gave me a completely different perspective on the black ribbon of rock my dad used to point out. It was the foundation of a massive, complex operation. As superintendent, my grandfather carried the weight of overseeing the development of three large earth-moving machines: the Gem of Egypt, the Silver Spade, and the Mountaineer. He also developed the largest cleaning company in the world at the time.

My grandfather had degrees in mining engineering and metallurgy from the University of Pittsburgh. He had to understand the unique characteristics of the Ohio coal while maintaining a constant awareness of the environment and the safety of his workers. Knowing my grandfather was out there, directing the immense effort required to extract the energy that built the modern world, connects me to the region’s industrial history in a very tangible, deeply personal way.

What remains in the ground

Today, the story of the Pittsburgh seam is mostly written in the past tense. After more than a century of intense, relentless extraction, most of the mining operations have ceased. The coal that was easy to get is gone. The U.S. Geological Survey (USGS) tracks the remaining resources of the Pittsburgh coal bed. While miners have exhausted much of it, the survey’s data profiles show that the largest remaining deep-minable reserves are in Washington and Greene counties in southwestern Pennsylvania, just south of Pittsburgh. There are still billions of tons of coal locked away there. However, the world has changed. Economics and a shift toward different energy sources will probably keep that coal exactly where it is.