This is part of our Road Trip 2018 summer series "Taking It to Extremes," which looks at what happens when people mix everyday tech with insane situations.

The trunk of my rented Camaro looks too small to fit a 5-foot-tall saguaro cactus.

It's a bit after 7 in the morning, and I'm at Saguaro National Park, outside Tucson, Arizona, where the temperature's already pushing 100 degrees. I'm surrounded by cacti ranging from a few inches high to more than 40 feet tall, and wondering how anyone manages to pull off a cactus theft. Because apparently, that's a thing.

You'd need shovels and a truck and definitely something like a heavy tarp to keep the needles away from your puncturable skin.

People do steal cacti, though. Saguaro cacti are particularly prized on the black market, where they can fetch anywhere from $500 to $2,000 a piece.

Eight years ago, rangers came across a trailer parked along a road in the park and found eight saguaro cacti inside. The rangers arrested the would-be poachers and even got convictions.

"That led to a whole conversation about the fact that most people who'd steal cactus from the park wouldn't be so brazen or dumb," says Ray O'Neil, chief ranger of the park.

The thing about national parks is that they belong to everyone — but that doesn't mean they're yours or mine to raid. Pick a park, and there's probably something the National Park Service is trying to keep people from stealing. In 2012, someone used power saws to chisel out four Native American petroglyphs, each about 3,500 years old, from Volcanic Tablelands in central California. Last year, thieves made off with ancient fossil footprints from Death Valley National Park.

Then there's the case of John Laroche — better known as the orchid thief from Susan Orlean's 1998 book of the same name — who became obsessed with the extremely rare ghost orchid. He stole the orchid of his desire from Florida's Fakahatchee Strand State Preserve with the idea of cloning it and, you know, making money.

For some reason, people feel compelled to grab something from our nation's parks and national monuments, whether it's prehistoric petrified wood, arrowheads, archaeological artifacts, wild ginseng roots or, as mentioned, cacti.

The NPS tracks crime reports by categories, including one called Resource/ARPA violations, which is what cactus and fossil theft fall under. In 2017, the agency tallied 1,459 such violations, but that doesn't mean it's an accurate count. After all, who could know exactly how many ginseng plants there are in Great Smoky Mountains National Park?

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"In the scheme of the 330 million people who visit our parks every year, taking arrowheads, redwood burls, ginseng and petrified wood is a small but serious problem," says NPS public affairs officer Jeffrey Olson.

Small but serious can escalate, though. If you've never heard of the Fossil Cycad National Monument, that's because it no longer exists. Located in the Black Hills of South Dakota, the park had the largest deposit of a fossilized, fernlike plant called a Cycad. But so many people lifted the fossils that the park was decommissioned as a national monument in 1957.

It's why national parks across the country have been devising ways to protect their unique resources. Here's a look at what Saguaro National Park, Petrified National Forest, Great Smoky Mountains National Park and Joshua Tree National Park are doing to keep their natural and historic treasures safe for new generations — and out of car trunks.

Tag!

A saguaro cactus, particularly for someone who didn't grow up around them, could hardly look more foreign.

They've been known to reach nearly 80 feet tall, sprouting arms at unexpected angles that, in turn, sprout smaller arms and nubs. They grow slowly. An inch-and-a-half-tall cactus might be 10 years old — and reach its full 45-foot height when it's 200 years old. That means I could be standing in front of a plant that got its start when James Monroe was president of the US.

Erin Carson/CNET

The saguaro is also iconic — this is the cactus of Western lore.

"It's a prized landscape item, and they're expensive so it becomes a target for unscrupulous people," Kevin Dahl, senior program manager at the National Parks Conservation Association, tells me over the phone when I ask why someone would steal a cactus.

Poachers who manage to dig up a saguaro stand to make a big chunk of change. The average black market value for a saguaro is $100 a foot, plus another $50 to $100 for each arm. A shady landscaping company could just dig up a cactus by some out-of-the-way roadside and pocket the money it would have paid a reputable nursery, Dahl says.

I wonder who gave Arizona the right to be so beautiful.

This is totally illegal, according to the Arizona Native Plant Protection Act. If you're caught breaking the law, you can end up with fines or jail time.

But back to that trailer full of dug-up saguaros: It gave rangers the idea of tagging cacti the way you'd tag your pet.

It costs about $7 to tag a cactus. I watch district ranger Jeff Martinelli show me how they do it. It starts with a thin, pill-shaped microchip that's barely a half inch long. No batteries needed. Martinelli loads the PIT Tag (Passive Integrated Transponder) in a large needle attached to a yellow gun, presses it into the side of the cactus and pulls the trigger. That pushes the tag into the flesh of the cactus.

Each tag has a corresponding number that's kept in a database with GPS coordinates. When Martinelli waves a gray, paddlelike scanner over the cactus, it beeps. If a nursery were doing this, they'd know the cactus came from Saguaro National Park.

"If poachers know it's going to be difficult to sell them at nurseries because the nurseries are either calling us or have scanners of their own, it makes it more difficult for them to make money," he says.

Erin Carson/CNET

Sometimes rangers will find a hole in the ground and check it against Google Earth to see what used to be there.

The tags are mainly a deterrent since it wouldn't be feasible to tag all the estimated 1.9 million saguaro cacti in the national park. (So many that I wonder what would happen if they ever became sentient and rose up against their human oppressors.) Rangers mainly go for the ones they know will appeal to poachers based on the cactus' location and physical attributes. They're hopeful some poachers won't want to run the risk of stealing a chipped cactus.

Rock out

Next up is a four-and-a-half-hour drive to the second stop on my tour of Parks People Steal From: Petrified Forest National Park, in northeastern Arizona.

The national park is home to the world's largest collection of petrified wood, artifacts of an ancient forest buried beneath a river system approximately 225 million years ago, during the Triassic era.

At the visitor's center, I meet with Bill Parker, chief of science and resource management, and museum curator Matt Smith.

NPS/Petrified National Forest

The park's been battling something of a PR problem. Stories about people picking the park clean were hurting its reputation. That got Parker wondering just how much of the fossilized wood — which looks like multicolored jewelry Mother Earth might wear -- had been carried off by light-fingered visitors.

He knew that petrified wood occurs only in certain rock layers, which means it never would have been found across all of the national park's 230 square miles. Were some areas getting an undeserved rap? The only way to know for sure was to do some time traveling.

"How can we go back in time and see where there was wood?" says Parker. "The obvious choice was photography."

The first photos of the area were taken in 1880. Going through the park's archives, Parker and others were able to match locations and vantage points with old photos, many of them taken by conservationist John Muir in 1905 and 1906, when he and his daughter lived nearby.

Erin Carson/CNET

It turns out, the theft problem wasn't as bad as they'd thought. In his office, Parker shows me side-by-side photo comparisons — old black and white images and newer photos from roughly 2007, showing more or less the same arrangements of petrified logs.

But that doesn't mean theft isn't a problem. Park caretakers often catch people in the act, sometimes tipped off by other park visitors. In 2015, the podcast Criminal interviewed Smith and park protection officer Melissa Holes about the issue. Holes described confronting a woman who had stuffed fossilized wood down her shirt.

The park also knows that people are stealing because some guilty parties mail back the jewel-like fossils with apology letters. Some folks returned them simply because they felt bad. Others thought they'd been cursed and recounted the terrible things that had happened to them. Smith received one on jail stationery.

"Ultimately, they're from people trying to right a perceived wrong and are trying to do the right thing," Smith tells me.

You need to connect an identity with the actual crime. Jason Theur

The returned petrified wood (detailed in the book, "Bad Luck, Hot Rocks") are put in something called a conscience pile that's now squirreled away at the south end of the park. The wood ends up there because putting it back would compromise archaeological and geologic research.

Jeanne Swarthout, board chair of Friends of Petrified Forest National Park, explains that when the rocks are removed from their original location, they become pretty useless.

"Without knowing where they came from, we can't put them in the context of the scientific study," she says. "Whether you return them to us or not, we've lost that provenance and we'll never get that back. We lose a story."

Jewel tones

I'm eager to see some petrified wood for myself, which means driving 20 miles through the Painted Desert and the Blue Mesa to the Crystal Forest, which all sound like destinations in video games. Not that I play video games.

At the Painted Desert, a little boy tells his family, "This is like Mars!"

It might as well be. Every time I pull over, the view bowls me over. Fifth-grade geography terms prove insufficient and, for a rare moment, I have no idea how to describe the things I'm seeing. Later I find out that some giant mound-thingies with colorful blue, red, and gray striations are called the Tepees.

Erin Carson/CNET

But when I finally overcome my need to pull over every few yards and wonder who gave Arizona the right to be so beautiful, I spot the first pieces of petrified logs, casually laying out in the sun.

I'm parked at the Crystal Forest, a roughly 1-mile-long trail with petrified wood scattered everywhere. It reminds me of my folks' backyard in Tennessee just after tornado season, when my father has diced up fallen cedars into 2- and 3-foot-long chunks with a rented chainsaw.

Tourists lumber down the trail, toting water bottles and cameras, yelling at their kids to get off the logs and stay on the path. You really have to pause and imagine how this place could ever have supported a prehistoric forest. And that maybe, just maybe, a Coelophysis stopped to pee on the log you're looking at.

Looking closely at some of the wood, you can catch orange, blue, purple and red striations. You can still see the tree rings.

Root out crime

Not everything in danger of being stolen is historic.

In Great Smoky Mountains National Park, which lies along the border of Tennessee and North Carolina, poachers are after the wild American ginseng that grows there. A pound of good, dry ginseng can go for $600, with prices climbing as the season wanes.

Ginseng purportedly lowers blood pressure, boosts energy and helps ease digestive problems. Buyers are after the wild stuff, which tends to be more gnarled than the slender, homegrown variety. Asia drives much of the demand, but there's local demand too, says district ranger Joe Pond. In Appalachia, folks even stick it in moonshine.

Enlarge Image North Carolina Department of Agriculture

The park's been trying to ward off poachers for years. They can't put a number on how much ginseng gets stolen every year, but they've noticed that the plants they're confiscating keep getting younger, in the 3- to 5-year-old range, as opposed to decades old. Ginseng can live upward of 30 or 40 years. That leads them to worry that the more mature plants are becoming scarce.

"If they harvest that root during that time period, then they've not only killed that particular plant, but it can't perpetuate itself," Pond says. A plant that's picked too young hasn't had time to produce berries with the seeds that will grow into new plants.

To deter and prosecute poachers, the park's been using science in the form of marking roots. Every year, the park's service staff and folks from the State of North Carolina go on a "marking blitz." They'll push aside dirt and expose roots of plants in certain patches, and spray them with an adhesive. They then apply an orange powder made from dye and silicon-coated chips. The dye gets absorbed into the roots, and glows orange when examined under a blacklight.

That makes it hard for some guy to claim he's just passing through the park with ginseng he dug up from his uncle's yard.

When tech isn't an option

It's easy to see technology as a cure for all ills. There are situations, though, where it just doesn't work.

Take Joshua Tree National Park, located about an hour outside of Palm Springs, California. The park, which has plenty of natural attractions plus a slew of old mines and homesteads abandoned by prospectors more than 100 years ago, battles both vandalism and theft. Park-goers have been known to tag boulders and walk off with artifacts— maybe a tin can found at an old homestead.

And as much as park law enforcement would like to toss up sensors everywhere, they can't, says cultural resources branch chief Jason Theuer.

Theuer worked in Petrified Forest National Park from 2007 to early 2011 and can compare the two. Petrified Forest has one main road. You can't camp there and you can't just wander off.

Petrified Forest also has sensors placed strategically along gated sideroads, so rangers know when people have strayed where they don't belong.

Joshua Tree has far fewer restrictions. Visitors can pretty much go wherever the spirit takes them.

"We are also the size of the state of Delaware, so response time is a little tricky," Theuer tells me over the phone.

Size isn't the only challenge.

Say you put up a trail camera — a fairly common tool for national parks — and catch someone looting an archaeological site. You've got a picture but not a name. That means you also need cameras in parking lots and at entrances so you can capture images of cars' license plates and the faces of people riding in them.

"You need to connect an identity with the actual crime," Theuer says.

And don't even think about microchipping everything in the park. "We have 2,000 archeological sites. Hundreds of thousands of artifacts. Are we going microchip every artifact? That's crazy."

So when tech doesn't pan out, group psychology can sometimes do the trick.

In late 2011, for example, vandals began scratching graffiti into Barker Dam, built by ranchers in 1900. Visitors saw that as a license to vandalize. Within three years, people's names were spread across into the dam's walls — Ashley, Adam, Derek, the Desert Sun reported.

Friggin' Derek.

Nearly the entire surface of the dam was covered in graffiti.

"Once a few people saw that one person had done it, it was OK for them to do it, too," Theuer says. He even caught a couple in their late 50s mid-scratch one day.

The park needed to stop people's urge to scratch. To do that, it started a process called in-painting – dabbing dots of acrylic paint, the same shades as the surrounding areas, inside the scratches. The graffiti is almost invisible.

They haven't seen any more graffiti since.

Up near California's border with Oregon, rangers at Redwood National and State Parks are trying to stop poachers from carving out the trees' valuable burls – essentially the outgrowth of a single bud that failed to develop into a branch, which then divides and redivides until it forms a bulge.

NPS

Poachers can sell the burls to dealers and shops where they get turned into bowls, plates, clocks, coffee tables.

In 2013, poachers felled a 400-year-old tree to get their hands on a 500-pound burl that was 60 feet up. It was one of 18 known cases of burl theft in the park. The next year, thieves carved out 21 burls from four trees.

Things get complicated when you realize this is an old-growth forest, with redwoods that live, on average, for 500 to 700 years. About 96 percent of the original old-growth coast redwoods have been logged, and Redwood National Park contains 45 percent of California's remaining protected old-growth redwoods. The burls are essential for reproduction. New trees grow from the burls when the parent tree dies.

In 2017, researchers made a series of recommendations, including installing closed-circuit TVs and listening devices that could detect the sound of a chainsaw.

None of the recommendations have been actionable, says Leonel Arguello, joint chief of resource management and science at Redwood National Park.

"The roads are not gate-able," he tells me over the phone. "There's no existing technology and/or staffing to keep people out 100 percent of the time.

"There is really nothing that can help us other than good old forensics," he says, explaining how they match the grain of a burl to a tree that's been damaged, or compare chainsaw marks. Those techniques can help them get convictions, but they're can't prevent the destruction.

You can't take it with you

Back at the visitor's center at Saguaro National Park, I hang around for a few minutes to mooch off the air conditioning. One of the folks behind the desk announces the next screening of a short, informational film that talks about the cacti and their relationship with Native Americans. When it ends, the projector screen slowly rolls up into the ceiling and the curtains open to reveal an unobstructed view of the land. For a split second, before people start reaching for their backpacks and purses: reverence.

Antonio/E+/Getty Images

In less than 48 hours, I'll be on a plane headed back to my pocket of the universe— an ivy-covered porch and an inch-tall barrel cactus, legally purchased.

It bends the mind to experience lands like this and just walk away. I think of the future parade of visitors who will have their own personal experiences that are, in a way, not their own at all.

So I pay $3.99 for a magnet showing some cowboys and saguaro, get in the Camaro and drive away.

All legal and guilt-free.

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