When Tim Kovar, perhaps the world’s most sought-after professional tree climber, saw recent headlines about people illegally ascending giant redwoods in California, he experienced a familiar emotion: frustration.
Kovar, 54 , says the irresponsible practice—which has been labeled “ninja climbing” in recent years—has attained popularity multiple times over the past three decades. The latest resurgence is particularly repugnant, and familiar to anyone who has followed news coverage of online influencers acting carelessly in outdoor places. “These guys are seeking out the biggest, baddest trees to ‘conquer’ and posting videos of themselves doing it online,” Kovar says. “It’s disrespectful to nature and to the scientific researchers whose life’s work is up in those trees.”
According to SFGate, a recent “braggadocious” YouTube video captures an illegal climb of massive trees that is “full of self-satisfied narration.” The clip follows a tree climber named Simeon Balsam and ten others who illegally scaled some of the tallest trees in California’s Redwood National and State Parks in 2022.
The trees being targeted by illegal climbers are already in danger of being loved to death by tourists. They include Hyperion, the world’s tallest known living tree at 380 feet, which is located deep inside the park. Officials closed off public access to the tree in 2022, when hikers using unauthorized trails destroyed the surrounding forest. Frequent foot traffic also degraded the 800-year-old behemoth’s base.
According to SFGate, a sizable portion of ninja tree climbers are professional tree maintenance workers—called arborists—just like Kovar. They don’t actually ascend the tree’s trunk and limbs, but instead climb a rope that they’ve shot up into the canopy using a crossbow. Arborists ascend the line using the same jumars that big-wall rock climbers and alpinists often use in steep terrain. They wear a specialized harness, called a saddle, that offers protection in case of a fall, and also gives them a place to sit when they are enjoying the canopy while suspended in midair by a rope.
Kovar teaches this technique, called technical tree climbing, to outdoor enthusiasts as well as professional arborists. He says the style of ascending causes the least amount of damage to the tree. But technical tree climbing has downsides. It’s forbidden in National Parks and in most State Parks without a permit. And those who ascend high into a tree’s canopy impact a delicate ecosystem—one that has no natural protection against human disturbance. One accidental boot kick to a branch is all it takes to destroy a rare, 500-year old lichen or moss mat.
“Think of it as a coral reef,” says Kovar.
Some of the gear commonly used for technical climbing, like gaffs—steel spikes worn on the legs for added grip on the tree trunk when cutting branches—can also cause inadvertent damage to the tallest trees.
“Tree bark is thinner two-hundred feet above the forest floor,” Kovar says. “Spiking will penetrate the cambium layer, leaving a wound that insects and beetles can enter.”
As for the entitled notion held by some ninja climbers that America’s largest trees are theirs to climb, Kovar says, “There’s no place for that at all.”
Kovar says he first saw ninja climbing appear in the mid-nineties, but back then the practice wasn’t illegal. At that time, he was working at Tree Climbers International in Atlanta teaching students the proper way to ascend trees using a rope and saddle. In his free time, Kovar visited nearby national forests with his colleagues. They would find a big tree and use their gear to climb it. “We didn’t exactly have permission,” Kovar says, “but trees in national forests are open to climbing, so it was a fun way to use our skills to connect with nature.”
Kovar and his crew were climbing oak and hickory trees that are native to the U.S. Southeast. They were not climbing endangered Sierra redwoods protected by the National Park System. And social media didn’t exist back then. If someone climbed a massive tree, its location would remain unknown and unadvertised.
Kovar has since moved to Oregon, where he founded Tree Climbing Planet, a travel and education company through which Kovar leads tree-climbing clinics and guides trips to places like the Amazon. He regularly guides clients on a trip to climb an old-growth redwood tree called Grandfather near Santa Cruz, California, specifically chosen for its resilience to climbers.
After author Richard Presto featured Kovar in his bestselling 2008 book about the redwoods, The Wild Trees: A Story of Passion and Daring, Kovar was flooded with inquiries from people wanting to climb redwoods. His belief that he could teach students to safely ascend one of the trees led him to Grandfather, which sits on private land.
The location is ideal because it’s at the southern end of redwood habitat, where it’s not as lush, and it’s up in the mountains, where it’s drier. “In that environment, there’s less of an ecosystem up there—we’re not having to manage for things like big moss mats and salamanders,” Kovar says. “But you still get the amazing canopy architecture where an entire separate tree is growing off of a huge bough.”
He opened Grandfather to climbing in 2014, and follows a strict protocol to minimize damage. The tour is only available for nine days a year, in early March, before the an endangered bird called the marbled murrelet, which nests in coastal old-growth trees, begins its mating season. Kovar takes up four people at a time, accompanied by a biologist who serves as a guide, educating guests about the unique flora in the canopy. He believes the experience helps foster a conservation mentality while doing minimal harm to the tree. “People come down a little more connected to nature and a little more connected to themselves as well,” he says.
In 2015, when publicists for rock climber Chris Sharma contacted him about making a film about a first free ascent of a massive redwood tree, Kovar was concerned. “They say no publicity is bad publicity, but I disagree,” he says. Kovar worried that the exposure would bring even more people, and more damage, into sensitive old-growth ecosystems. He connected Sharma with researchers at UC Berkeley to find a way to do more good than harm.
Sharma ended up free-climbing a redwood in a city park in Eureka, California, and helping scientists gather data from the canopy. The short film, produced by Red Bull, was viewed more than 1.5 million times on YouTube. It included an option to donate to fund new research on the effects of drought on redwoods. “If done correctly, and in the right setting, climbing into old-growth redwood trees can have a very positive impact,” Kovar says.
He thinks education is still the best way forward. “People love big trees and they want to see and experience them, and you can’t blame them,” he says. “But they need to understand that they could also be killing them.” The way to reduce your impact is to go with a guide. Besides his own company Tree Climbing Planet, and his former employer Tree Climbers International, Kovar points to Expedition Old Growth as another outfit operated by nationally certified arborists trained in educating the public and minimizing the impact on trees.
For those enamored with the do-it-yourself spirit of ninja climbs, Kovar says by all means, go for it. “There’s plenty of trees in the forest.” Just do it legally, and stay out of the old growth.