On the side of the hill, William S. Krippen was doing the one job the whole enterprise existed for. He was peeling bark. It was the 30th of June 1893, the last weeks of the peeling season, and he was working the bark woods at L.

S. Mills in Potter County, Pennsylvania. A short distance away, other workmen were felling a tree. When it fell, it struck the trunk of another hemlock standing nearby.

The top of the falling tree snapped off. Instead of following the rest of the trunk to the ground, it flew back toward the hillside where Krippen was working. It struck him and he was killed instantly. He was the son of Ross Krippen of Potter Brook, and he had been married only a few months.

The Wellsboro Agitator printed the news on the 12th of July in four sentences. The last of them said only that Krippen had been married a few months ago. He had not been felling the tree. He had been peeling bark, and the danger had come from the next tree, from the tree beside it, and from the speed the season demanded.

To understand how a man could die that way, you have to start with leather. In the 19th century, leather was everywhere. It was in the soles of every pair of boots and shoes in the country. It was in every harness on every horse that pulled a plow, a wagon, or a streetcar.

It was in saddles, buckets, fire hoses, and the long belts that carried power from the steam engine to every machine in a factory. An army marching to war needed leather. A farm needed leather. A mill needed leather.

In 1868, the tanneries of just three counties in the Catskills—Sullivan, Greene, and Delaware—tanned an estimated two million hides. Sullivan County was so proud of its trade that its historian, James Eldridge Quinlan, is quoted as saying, “The Civil War was won with boots tanned in Sullivan County. ”

Rawhide does not stay hide for long. Left alone, it stiffens, rots, and stinks.

To turn it into leather, it had to be tanned, soaked for months in a liquid strong with a substance called tannin. Tannin binds to the fibers of the skin and turns a perishable animal hide into something that can last a lifetime. For centuries in Europe, that tannin had come from the bark of oak trees. But in 1805, the British chemist Humphry Davy showed that the bark of the hemlock tree would do the same work.

In the forests of the American Northeast, that was a discovery worth a fortune. Hemlock bark carried around ten to twelve percent tannin, and the mountains of New York, Pennsylvania, and Michigan were covered with hemlock. There was a problem with the rest of the tree, though. To a 19th-century lumberman, hemlock was a poor second choice.

Until about 1850, white pine was the leading tree in the Pennsylvania woods, and as long as there was pine to be had, the lumber industry avoided hemlock because of its quality. And there was no easy way to move a hemlock log out of the mountains. There were no logging railroads yet and no trucks. A hundred-foot trunk was worth only what someone would pay for it at the bottom of the hill, minus everything it cost to get it there.

For a tree the lumber trade did not want, that number was close to nothing. The bark was different. The bark could be cut into short pieces, dried, stacked, and hauled on a wagon. It held the one thing in the whole tree that someone was already paying for.

So the tanners did something that sounds backwards today. They did not bring the bark to the leather. They brought the leather to the bark. They built their tanneries in the middle of the hemlock forests, next to a creek for water, and shipped the raw hides in.

The most famous of them was Zadok Pratt. In 1824, he bought a site on Schoharie Creek in the Catskill Mountains of New York, chosen for its hemlock and its water. His tannery building was 550 feet long and 43 feet wide, with 350 vats, 12 leeches, and two bark mills. The building went up in 82 days.

A historical marker there credits the tannery with 60,000 sides of leather a year, and over its life it employed some 2,000 people. Pratt’s tannery ran for about 20 years. In that time, it stripped the hemlock from 6,666 acres, more than ten square miles of forest. One estimate puts its total at 100,000 cords of bark.

A cord, for those who have never stacked one, is a pile four feet high, four feet wide, and eight feet long. In the Pennsylvania woods, an average hemlock was reckoned at about a cord of bark. A big tannery could go through 50 cords in a single day. And a hemlock is a slow tree.

It commonly lives two or three hundred years, and one in Pennsylvania has been dated to 554 years old. A tree that had been growing since before the Revolution could be on the ground and stripped before the crew stopped for supper. So the question became how to take the skin off a hundred-foot tree fast and by hand. The work could only be done in one season.

In spring, when the sap began to run, the inner layer of the bark loosened from the wood. The men called it slipping. Bark that was slipping came away in long, clean sheets. In the dormant months, the same bark was locked to the trunk and very hard to remove.

In the Pennsylvania woods around Sheffield, peeling began around the 15th of May and ended somewhere between the 4th and the 25th of July, depending on whether the summer was wet or dry—seven to ten weeks. Everything a tannery needed for a whole year had to come off the trees in that window. In the Warren County woods, the work was done by crews of five, and every man had one job. Two sawyers went first.

They chose a tree, cut a notch on the side where it was meant to fall, and then pulled a long crosscut saw back and forth through a trunk that could be four feet across until the hemlock leaned, cracked, and came down across the slope. Then the knot bumper went to work. Hemlock carries dead branches far up its trunk, and every stub left in place would tear the bark. The knot bumper walked the length of the fallen tree with a double-bit axe weighing three to four and a half pounds, knocking the knots off flush with the trunk.

He also turned the log when the crew needed to reach the underside. Then came the bark fitter. His job was to lay out the bark for removal. He cut a ring around the trunk, then another farther along, and then another all the way up the tree, so that the bark came off in lengths of four feet and two inches.

Between the rings, he cut a straight line down the length of the trunk, so each section had an opening to start from. And then came the peeler. His tool was called a spud. It had a steel head, rounded or dish-shaped, with a sharpened edge on a handle of hard wood such as hickory or ash.

Some were made from an old buggy spring with one end ground sharp. The peeler drove the edge into the slit the fitter had cut and slid it under the bark, between the bark and the wood. If the sap was running, the section lifted off the trunk in one curved piece, like the stave of a barrel. Then he moved on to the next section, and the next, all the way to the top.

Two men working together could fell trees and peel two or three cords of hemlock bark in a day. The pay followed the bark. Harry Paul Jefferson, who remembered the peeling crews of the Warren County woods, said the men were paid by the cord, by check and not in gold, and that it worked out to around a dollar and a half or a dollar seventy-five a day. A crew that peeled more earned more.

A crew that stopped to look up earned less. The sheets of bark were stacked on the hillside to dry. Once they had cured, they had to come down the mountain. On steep hillsides, the crews built wooden shoots and slid the bark down them.

On gentler ground, it went onto wagons fitted with stake cradles, piled as high as the men could reach. A two-horse dray could haul a cord and a half or two cords at a time. In the Catskills, much of the bark waited for winter, when it went down on sleds behind teams of oxen. Sullivan County, which had more tanneries than any other county in New York, was said to have more oxen than any other county in the state.

Around Sheffield in Warren County, Pennsylvania, planks were laid over the dirt roads so the loaded wagons would not sink. One of those plank roads ran eight miles from Sheffield through Starbrick to Cherry Grove. A street in Sheffield is still remembered as the Plank Road. Sheffield’s tanning boom had started in 1864.

That was the year the Philadelphia and Erie Railroad was completed through the town, and the brothers Webb and Walter Horton arrived and began buying hemlock land. Farther west in Wisconsin, the bark went to the railroad in winter on sleds. A single loaded sled could weigh as much as 23 tons. At the tannery, the dried bark went into the bark mill and was ground.

Water was run through the ground bark in large tanks called leeches, and what came out was a brown liquor full of tannin. At Pratt’s tannery, six heaters kept that water warm. Later tanneries used steam to speed up the leeching, which cut the time to draw the tannin out of the bark from four days to two. The hides needed their own preparation.

They were soaked, the hair was loosened and scraped off over a curved wooden beam, and the men who did that work were known as beam hands. Then the hides went into vats of the bark liquor and stayed there. In the early years of the industry, a hide spent about six months in the solution before it came out as leather. The numbers were enormous.

The Tionesta tannery at Sheffield went through 8,500 cords of bark a year, about 29 cords for every working day. One local history reckons that a single tannery of that size needed about 15,000 hemlocks a year. And the hides came from everywhere. The tannery at Proctor, Pennsylvania, deep in the hemlock country of Lycoming County, tanned hides shipped in from Mexico, Argentina, and China.

In the Adirondacks of New York, there were 153 tanneries in 1850. In northern Michigan, the trade arrived later. At Boyne City, a tannery opened in 1904, and by 1907 it was turning out six million pounds of leather a year, while ships carried Michigan hemlock bark across the lake to the tanneries of Chicago, Milwaukee, Racine, and Kenosha. And here is the part that is hard to believe.

After the peeler finished, the crew walked away. The bark went to the tannery. The trunk stayed exactly where it fell. A hundred feet of hemlock, four feet thick at the butt, lay on the mountainside with its skin gone, bleaching in the summer sun.

The next tree came down beside it, and the next one beside that. Season after season, the hemlock logs were left to rot in the woods. The Catskills alone lost an estimated 70 million hemlocks to the tanning trade. In Pennsylvania, the crews left whole mountainsides strewn with peeled trunks, dead branches, and scraps of bark.

That was the system, and it worked. What it cost the men who worked under those falling trees was written down in 1893 in four sentences in a small-town newspaper. The newspaper was the Wellsboro Agitator, the weekly paper of Tioga County, and it followed the peeling season the way it followed the weather. In the spring of 1890, it reported that Truman Hamlin and Ansel Gunn had started a job of peeling 400 cords of bark.

Eli Robbins had moved to Landrus, where he had a job of bark peeling. And Leonard Harrison, on his timber tract along Pine Creek, told the local paper what he expected from the coming season: his crews would peel about 3,000 cords of bark. The trees on that land were eastern hemlocks. In the old forest, they commonly stood a hundred feet tall or more, and many were four feet thick at the base.

Every one of them was felled by hand with an axe and a crosscut saw. For most of the 19th century, crews like his did something with those trees that seems impossible today. They took the bark and only the bark. The trunks stayed where they fell, a hundred feet long, naked and pale, thousands of them on a single tract, left on the hillsides to rot.

In the same columns, sometimes in the same issue, the paper also reported what that work cost. On the 27th of May, it noted that John Bailey of Lutonia had been struck by a falling tree in the bark woods, and his collarbone was broken. On the 17th of June, it reported that Oliver Hall had been struck a heavy blow on the head. A large limb had fallen from a hemlock while he was peeling bark for Ezra Swope.

That was the danger nobody could fully avoid. A hemlock is a tall tree with a crown full of dead limbs. When a crew felled one, it shook every tree around it, and dead branches could break loose high above and fall onto the men below. And a peeling crew was always working close to the next tree coming down, because the whole job was a race against the end of the sap.

Eleven years earlier, in June of 1879, the same paper had reported the death of Jordan Shive. He was a farmer of Jackson Township, more than 60 years old. He had walked into the woods where his workmen were peeling bark. They were busy and did not notice him until the tree had already started to fall.

A warning was shouted, and it only seemed to confuse him. The tree came down and crushed him to the ground. Nobody kept a count of how many bark peelers died that way. They were paid by the cord, and when one of them was hurt, the record of it was a few lines in the local paper, if it was recorded at all.

The cases that made it into print are the ones we know about. The real number was certainly higher. And the bark woods kept growing. By 1880, Pennsylvania alone had 890 tanneries.

One firm, the Horton, Currier Company, owned 125,000 acres of forest to keep its tanneries supplied. The tanneries built whole towns around themselves. In 1868, the Boston tanner Thomas E. Proctor founded a company town on Plunkett’s Creek in Lycoming County and called it Proctorville.

It had 120 company houses that rented for two dollars a month. The several hundred men who worked at the tannery earned from 50 cents to $1. 75 a day. The bark came in on wagons and sleds from as far as eight miles away.

The finished sole leather went out eight miles in the other direction by horse and wagon. In 1893, the owners of some 200 tanneries joined together into one corporation, the United States Leather Company. Thomas Proctor became its first president. It was capitalized at $130 million.

It controlled about three-quarters of all the bark land, and it was one of the original companies of the Dow Jones Industrial Average. It took about two and a half cords of bark to tan a hundred hides. And then something strange happened to the wood. By the 1880s, the white pine was nearly gone, and logging railroads were pushing into the mountains.

Suddenly, hemlock lumber had a market. In 1885, a Buffalo businessman named Frank Goodyear began buying up thousands of acres of virgin hemlock in north-central Pennsylvania. He built a sawmill at Austin in Potter County, the same county where William Krippen died. By the late 1890s, it was listed as the largest mill in the state.

The Goodyear operations ran 75 miles of logging railroad and employed 2,400 men. Now the logic was turned upside down. The trees were cut for their lumber, and the bark became the byproduct, shipped to a sole leather tannery at Costello. In Michigan, a paper company bought peeled hemlock logs by the million feet and hauled them out by rail.

In Pennsylvania, peeled logs that had been left to dry on the mountainside were skidded down to the tracks. For the first generation of hemlock forests, it came too late. Their trunks had already rotted where they lay. The end of the bark woods came from two directions at once.

The first was the forest itself. The hemlock was running out. At Proctor, the old-growth hemlock was exhausted by 1898, and the tannery was closed and torn down. In Pennsylvania, the crews left mountainsides covered in dry slash, and in the early 1900s, fires burned through around 350,000 acres of Pennsylvania forest a year.

In the Catskills, the tanning trade had nearly disappeared by the early 1900s. It left bare mountainsides, eroded soil, and creeks fouled with tannery waste. Much of that worn-out land was later taken over by the state and became part of the Catskill Forest Preserve. The hemlock never came back the way it had been.

Hardwoods grew in where it had stood. The second was chemistry. In 1884, a chemist named Augustus Schultz received patents for a way to tan leather with chromium salts instead of bark. In the early 1890s, it went into commercial use in the leather shops of Philadelphia.

Chrome tanning needed a fraction of the time, and it did not need a single tree. The bark peeling did not stop all at once. Some plants in New Jersey were still tanning with bark in the 1920s. In the mountains of West Virginia, the tannery at Paw Paw, which the United States Leather Company had taken over in 1893, was still turning out more than 500 hides a day in the 1930s.

It shut down for good in December of 1951. But the great days of the bark woods were over. The United States Leather Company went on for another half century through mergers and reorganizations. In 1952, it was liquidated, the only one of the original 12 companies of the Dow Jones Industrial Average to end that way.

The village of Proctor kept its post office until July of 1953. By 1970, it was described as a near-deserted old tannery town. And yet some of it is still there. Outside Prattsville, New York, Zadok Pratt had his own life carved into a rock face above the road.

The carvings are still there. Among them is an upraised arm with a hammer in its hand, which the historical marker calls a tribute to the working man. The hills around it were covered in hemlock once. Pratt’s tannery took the bark from more than ten square miles of them.

In Potter County, Pennsylvania, the Pennsylvania Lumber Museum still holds an annual festival in honor of the bark peelers. And here and there in the Catskills and the Pennsylvania Mountains, people still take an old spud and peel a hemlock by hand in early summer, when the bark is slipping. When they are done, there is a pale log lying on the ground, bare from end to end. For most of the 19th century, that sight was everywhere.

A hundred feet of wood, four feet thick, felled with an axe and a crosscut saw, stripped with a spud, and left on the hillside for the rain, because the only part anyone wanted was the skin.