Giant sequoias, native to the high-altitude slopes of California’s Sierra Nevada mountains, are the largest trees on the planet. In fact, they’re the largest living organisms on Earth. The General Sherman Tree in Sequoia National Park measures 36 feet in diameter at its base, stands nearly 275 feet tall and is more than 2,000 years old.

Today, California’s giant sequoias are a protected species, but a century ago they were viewed just like any other natural resource—something to be harvested for human gain. In the late 19th century, the United States was experiencing explosive growth. Western forests were sold off for logging rights to supply lumber for building the nation’s homes, schools and factories.

A single giant sequoia could provide 500,000 board feet of lumber, a bonanza for profit-hungry logging companies. But chopping down these mighty trees proved to be a herculean task. Milling the massive trunks and transporting the lumber down from the mountain was even more difficult. It required expensive feats of engineering like the 54-mile Sanger flume, the largest log flume of its day.

In the end, the logging of giant sequoias was a financial and ecological disaster. But that realization didn’t come until after thousands of the ancient trees were felled in what one writer described as “the greatest orgy of destructive lumbering in the history of the world.”

Not long after the California Gold Rush of 1849, rumors began to spread about groves of massive trees high in the Sierra Nevada mountains. According to descriptions, the trees were an even larger version of the towering coastal redwoods found near San Francisco. Redwoods were known to produce strong, high-quality lumber. Whoever secured the logging rights to these even bigger “redwoods” would be sitting on a goldmine, it was thought.

“Believe it or not, there was a time when all of the Sierra Nevada, like all the rest of California, was for sale from the federal government at almost no cost,” says William Tweed, author of King Sequoia: The Tree That Inspired a Nation, Created Our National Park System, and Changed the Way We Think About Nature.

“Land was sold under the belief that the best thing to do with it was to get it into private hands. If it was lowlands, it needed to be cleared of trees and farmed, and if it was uplands it needed to be logged. That’s what was best for the country and best for the economy.”

For logging, the federal government placed a limit on how much land any single person could buy, but savvy logging companies got around the regulations. They would recruit locals to apply for logging rights and then buy back the “dummy” contracts for themselves.

“There was definitely fraud,” says Tweed, “and it led to logging on a much bigger and more monopolistic scale than the government intended.”

That’s how an outfit named the Kings River Lumber Company secured the rights to log 500 acres of some of the biggest trees in the world.

Giant sequoias are only found in one place—a 250-mile stretch of forest along the Western slopes of the Sierra Nevada mountains. They grow at high elevation, between 4,000 and 8,000 feet, and are clustered into roughly 70 groves. Before logging came to the Sierra Nevadas, one of the largest and most majestic of those groves was the Converse Basin.

“Here were thousands upon thousands of patriarchal forest giants stretching so high they almost blotted out the sky,” writes Hank Johnston in his seminal 1966 book, They Felled the Redwoods. “Here was a sylvan paradise filled with colorful wildflowers, lush grasses, and a variety of animal life. Some timber experts say that the Converse Basin contained the finest examples of Sierra redwoods [giant sequoias] to be found anywhere on earth.”

For centuries, the Converse Basin was a hidden paradise. It sat at 6,500 feet in a bowl-shaped depression ringed with cedar, fir and more than 8,000 giant sequoias.

“It was a spectacular place,” says Tweed.

In 1891, the Kings River Lumber Company harvested 20 million board feet of lumber from lower elevations, mostly fir, pine and cedar. But given the expense of its logging operation, it still wasn’t enough for the company to turn a profit. In December of that year, the company announced that it would be extending its logging operation deeper and higher into the Sierras, where it had secured rights to the Converse Basin.

“We must increase our volume to justify the enormous investment of the mills, railroad and flume,” wrote a company official. “We plan to move our railroad to the northeast where the really big trees are located. Next season should be highly profitable.”

In 1892, the Kings River Lumber Company began logging the Converse Basin, home to giant sequoias with 15- to 20-foot diameter trunks.

“The best technology in the 1890s for cutting down these trees was a combination of hand tools and steam power,” says Tweed.

Loggers used the same technique to fell a giant sequoia that they used with smaller trees. First, they had to make a V-shaped “undercut.” To do that, they built a platform 25-feet high so they could reach the softer part of the trunk. Then two men—one left-handed and one right-handed—started chopping away with double-sided axes.

The loggers—mostly Swedish, Polish, German, Irish and Norwegian immigrants—worked 11-hour days, six days a week. It took each two-man crew several days to hack their way to the center of a tree, leaving behind an undercut tall enough for them to stand inside.

The same men would then go to the other side of the tree and grab each end of a long, two-handled saw. Heaving back and forth, they made one continuous cut back through the trunk toward the undercut. Every foot or so, they hammered in 24-inch steel wedges to prevent the tree’s incredible weight from snagging the saw.

When only a few inches remained between the back cut and the undercut, the loggers used even more wedges and powerful blows from a sledgehammer to topple the sequoia in the direction of the undercut.

“The crash was like the roar of a raging sea beating upon a rocky shore,” writes Johnston. “Dust and debris filled the air. The great stump, relieved of its burden of centuries, quivered for many minutes in a series of paroxysmal reactions. The ground trembled and shook as if struck by a mighty earthquake. A life, several thousand years in the making, had been snuffed out in a moment.”

The loggers soon learned that the biggest sequoias, when felled, would sometimes smash to pieces under their own weight. So they started making “felling beds”—clearing the target landing area of smaller trees and boulders, and even laying down branches and leaves to create a cushion.

“Chopping down a giant sequoia is just the beginning of the challenge,” says Tweed, “because now you’ve got a 200-foot long, 15-foot diameter log sitting on the ground. What do you do with it?”

The logging companies built a sawmill in the heart of the Converse Basin to rough-cut the downed logs into manageable-sized pieces. But first they needed to get the logs to the mill. Sequoia trunks were too big and heavy to be dragged by teams of horses, so that’s where steam power came in.

Outside the sawmill were two “steam donkeys.” These were large, steam-powered winches that used long cables to drag felled sequoia logs through the forest. To guide the logs on their journey, the companies built a network of “chuteways”—lanes made from parallel rows of smaller logs. “Grease monkeys” lubricated the chutes so fires wouldn’t spark from the friction of dragging the massive logs.

Once at the Converse mill, the logs were run through a 90-foot bandsaw, the longest saw in the world at the time. The rough-cut lumber was then loaded on train cars and hoisted up the mountain by another powerful steam winch. From there, the lumber took a short train ride down to Millwood, a California boomtown where the wood was finally cut into boards and set out to cure in the sun.

A tremendous amount of labor went into turning a giant sequoia into a pile of 2x4s, but it wasn’t over yet. The lumber still needed to travel 54 miles to Sanger, California, where it would be loaded onto railcars and shipped across America. There was only one way to make the last leg of the journey from Millwood to Sanger: the log flume.

The Sanger log flume was not the first of its kind. Starting in the mid-19th century, engineers built flumes to transport water from the mountains to irrigate farmland. Then the first logging operations constructed flumes for floating uncut logs down to sawmills from higher elevations.

But when the Sanger flume went into operation in 1890, it was by far the longest and most expensive log flume ever built. The price tag was a reported $300,000 (more than $10 million today) and required 9 million board feet of lumber to construct. The V-shaped flume was supported by 54 miles of trestles, some of them 100 feet high.

The town of Sanger dubbed itself “Flumeopolis of the West.”

“It was an enormous feat of engineering,” says Tweed. “This flume was unique in giant sequoia logging. You can’t begin to imagine how much capital went into developing this. It was a huge investment.”

At the top of the flume in Millwood, workers lashed together finished boards into bundles measuring up to 28 feet long and dropped them into the water. The ride was a leisurely float for most of the trip, but there were a few steep sections and sudden drops where the water rushed along the flume at 50 miles per hour.

In addition to lumber, people could also ride the Sanger flume. Mostly it was used to transport workers and supplies from Millwood to Sanger, but it was also a popular form of public entertainment (and the inspiration for modern log rides at amusement parks).

In 1897, a journalist from the Visalia, California Times wrote about his trip down the log flume:

“There is a splash and a gurgle as the suspended end drops into the water. A slip and the next moment you are going a mile every three or four minutes. As we approached the lower mill, the boat hit a steep pitch in which gravity took over and caused it to drop faster than the water. This slide was one of the great thrills of the trip.”

Kings River and other lumber companies logged the Converse Basin from 1892 through the early 1920s. They felled thousands of sequoias, but only a fraction of them ever made it to the mill. Sequoia wood is much more brittle than redwood, and many of the biggest trees smashed into unusable pieces on contact, even with the felling beds.

“There was a huge amount of loss in the felling,” says Tweed. “Estimates from the 1930s were that half or more of the wood was still on the ground; it simply wasn't worth picking up. That’s how wasteful it was.”

The logging companies and their investors sunk so much money into the mills, railroads and flumes that they tried to squeeze every last penny out of the Converse Basin.

“Business being business, once you’ve invested that much money, you have to keep trying,” says Tweed. “So they cut down pretty much the entire grove trying to find a way to make money cutting down the grove.”

When the slaughter was over, only one truly grand giant sequoia was left standing. Known as the Boole Tree, it was named after Frank Boole, a supervisor with Sanger Lumber. The story goes that Boole spared the tree as a reminder of what once stood in Converse Basin, but it’s more likely that the tree was simply too big and too awkwardly situated to chop down.

Eventually the federal government bought back Converse Basin and all of California’s giant sequoia groves to create Sequoia and Kings Canyon National Parks. Visitors to Converse Basin can still see reminders of the destructive logging—massive stumps and rotting logs—but also “young” stands of century-old sequoias reaching for the skies.

“We sold the forest for the good of the country and bought it back for the good of the country,” says Tweed.