Correction: An earlier version of this story incorrectly identified Sumatra and Borneo as the only places in the world where tigers, elephants and rhinos still coexist in the wild. In fact, those three animals can be found elsewhere, and there are no tigers on Borneo. This version has been updated.

At Way Kambas National Park, you can climb onto an elephant for a ride into the wild. (Ulet Ifansasti/GETTY IMAGES)

When a man with a machete silently joins us at the edge of the rain forest, my sister and I aren’t sure whether to be alarmed or comforted. We already have a guide and a park ranger accompanying us as we set off into Sumatra’s Way Kambas National Park. The mysterious machete man makes five.

The Indonesian island of Sumatra is one of the few places where elephants, rhinos and — of particular interest to Heather and me — tigers live together in the wild. Critically endangered, wild tigers are fighting to survive in the face of widespread poaching and forest-clearing. With this in mind, we’ve decided to travel to Sumatra to see what we can, while we can.

Before the trip, the eco-lodge arranging it warns us that it’s extremely unlikely that we’ll see any tigers. There are roughly 30 Sumatran tigers remaining in the 502-square-mile Way Kambas park, in southern Sumatra, and they mostly prefer to stay in the deep interior. Across Sumatra, there are fewer than 400 tigers left; they’re extinct on the nearby islands of Java and Bali. Sumatra’s tigers are smaller than their cousins elsewhere and have thicker black stripes.

Though getting a glimpse is a long shot, Heather and I are ready to try, hoping at the very least to spy a tiger paw print or claw marks on tree bark — any signs of the jungle cats will do.

Details: Sumatra, Indonesia

From the clearing, we hike single file into the park with the mysterious machete man at the rear, the ranger at the front. Following a trail not much wider than a machete blade, we cross patches of shoe-sucking mud and kick up finger-size leeches, which slow our pace, as we keep stopping to shake them off. We also stop often to look at macaques, a well-named slow loris (a lemurlike primate that we’re told has a toxic bite), small deer known as muntjacs, and blue-banded kingfishers. Some of the trees are rare tropical hardwoods that are highly valued by loggers. Overhead, we hear monkey and wild-bird calls. As we’d been forewarned, despite the machete man at our backs, there are no traces of any tigers, the very thing we most hope to see.

“Perhaps the tiger cams are the best way to see the tigers,” says our guide, Hari, once we’re back at the ranger station, offering the thought as a sort of consolation prize. Removing leeches from our clothes, hats and shoes as the machete man grills fresh fish on an open fire, we’re inclined to agree.

After lunch, we try a different route into the park. The five of us set off in a small boat that cruises slowly along the Way Kambas River, on glassy water the color of milky tea. Our wake barely rouses a mostly submerged freshwater crocodile. There are no muddy tiger footprints along the bank, but gibbons and long-tailed macaques spot us and move higher up into the trees.

With the help of a small laser pointer, Hari points out a gray python tucked into the hollow of a tree branch. Farther along, he spots two black-and-yellow mangrove snakes well hidden in dark undergrowth. The machete man, who’s manning the motor, maneuvers the boat so close that the branches whack us in the face.

“Very bad, very poisonous,” Hari says of the snakes, while again highlighting them with the laser pointer. We don’t need much convincing. Wishing that we had machetes of our own, we head back to the lodge, agreeing that it’s best to let sleeping snakes lie.

Among the rhinos

In the morning, Hari picks us up and promises that we’ll have better luck seeing Sumatran rhinos and elephants today. We follow a bumpy dirt road into the park, driving past more muntjacs, monkeys and crested fireback pheasants on our way to the Sumatran Rhino Sanctuary.

The sanctuary aids Sumatra’s endangered rhinos, which are considered one of the most threatened large mammals in the world. They are the smallest rhinoceros species — and considered the most vocal — and are also known as hairy rhinos because of the hair on their bodies. Less fortunately, Sumatra’s rhinos are the only species in Asia with two horns, making them particularly attractive to poachers. They’re hunted for their horns, which are ground into a power that’s used in traditional medicines and that some believe to be an aphrodisiac. Once found across Southeast Asia, Sumatran rhinos today number about 100, with only 25 to 35 at Way Kambas.

We’re fortunate enough to see one of them, a young 1,500-pound female that has come to the sanctuary for breakfast. Like other rhinos here, she’s being reintroduced into the wild following a period in captivity. Mostly solitary creatures, the sanctuary’s rhinos each receive a large wedge of rain forest to roam in, with the wedges radiating from a large circle, at the center of which is the sanctuary itself. This rhino is particularly prized as a young female that can produce offspring. Efforts to breed Sumatran rhinos in captivity have failed.

The rhino has returned from a night in the forest to eat mounds of leafy branches. She chews her food slowly while a sanctuary staff member tells a German documentary film crew and us that rhinos eat 10 percent of their weight each day, which is certainly food for thought. Curious about the gathered crowd, the rhino ambles over closer to us. Up close, her leathery skin is indeed marked by patches of dark hair. Her eyes are lively, and she’s surprisingly light on her feet. She cautiously investigates our small group and, fortunately for us, decides not to mark her territory with excrement (another Sumatran rhino characteristic). Instead, a sanctuary staffer briefly mists her with water; then, her curiosity satisfied, she lies down for a nap.

In the sweltering heat, the misting looks inviting, but we have elephants to see, and still hold out hope for tigers.

Elephant ride

A teeth-rattling ride in the SUV lands us at the Elephant Conservation Center. Along the way we encounter a few motor scooters that are nearly obscured by piles of branches, presumably used to feed the rhinos, heaped behind the drivers. We also pass lush forest and small patches of land cleared for farming, some marked by tall wooden platforms.

Hari informs us that the farmers use these platforms to keep watch over the fields at night to make sure that the elephants don’t trample their crops. Like the rhinos and the tigers, Sumatra’s elephants have had their troubles. They are critically endangered, with fewer than 3,000 Sumatran elephants remaining, about 200 of them in the Way Kambas park.

The clearing of forests for palm oil, illegal coffee cultivation and timber has dramatically shrunk the amount of open space available to the elephants, making them more likely to run into people who see them as a threat, particularly to crops. Poachers in search of elephant tusks, which are valued in the ivory trade, also use the crude roads cut into the forest to support the illicit farming and logging.

The elephant center aims to mitigate some of these issues and help elephants that have been injured by run-ins with humans. This year, it expects to open Indonesia’s first elephant hospital. Heather and I tour the center’s low-slung bungalows and let a baby elephant reach into our backpacks and pockets with its long trunk to consume our stash of bananas.

Then we climb aboard two resident elephants to explore farther afield. Our elephant drivers, or mahouts, guide us along a red dirt track, across swampy water and onto a grassy plain. In the distance, we can see pockets of grazing wild elephants.

“Any tigers here?” I ask the elephant driver, our elephants’ ears flapping as we push through high bushes.

“Maybe in the past you see droppings,” he says, pointing to the ground, “but now not too much.”

After an hour, somewhat saddle-sore from the ride, we head back to the elephant center, where the call to prayer from the mosque fills the air.

That night at the eco-lodge, my sister and I drink warm beer and toast our good fortune at seeing the elephants, rhino and other rare wildlife. A small cat wanders from table to table hustling scraps, and we agree that it will have to do for our tiger of Sumatra.

I head to the kitchen for more beer and stop in front of two white boards in the dining room. A long list of local wildlife covers one. On the other is a rough map of the area on which visitors have written in the animals they spotted. Some I wished I had seen, such as the colorful sun bear; others, like the spitting cobra, I’m glad to have avoided. And then I see it.

Near the eco-lodge, someone had written: “At 6 p.m., a tiger crossed the road 3m in front of motor bike.”

Finally, there it was. A Sumatran tiger sighting, one small sign of an all-but-gone ghost cat, tellingly written in not-so-permanent marker.

Biggar is a journalist in the San Francisco Bay area and in Washington.