We were cruising at eight thousand feet, low enough to make out individual trees in the rainforest below, when a towering wall of midafternoon cumulus arose before us.

There was no way around it — it was many miles wide — and no way over it because we were in an 84-year-old Douglas DC-3, arguably the most legendary plane ever mass-produced yet one without a pressurized cabin, which limited how high we could fly.

As the plane and the storm closed in on each other, Captain Joaquín Mosquera slid his window shut. When traversing clear skies, he hangs his elbow out of it as if he were driving an old pickup truck down a dirt road. That’s how riding in a DC-3 feels, too: like being pulled by a tractor through the sky.

This exact plane — one of only 16,000-or-so that were made — was the last operating a scheduled passenger service. As soon as I heard about it while on assignment in Colombia, I knew that I’d do whatever it took to get on board — both as a journalist and as an aviation geek.

The remaining few DC-3s mostly operate either as tourist novelty flights or in remote areas like the Canadian tundra, where they transport cargo only. But this one, operated by Aerolíneas del Llano — Plains Airlines — delivers passengers throughout far-flung corners of Colombia’s savannas and jungle.

I couldn’t help but wonder about the world in which this octogenarian plane still served as transport for people: Who were they — and did they feel any of the excitement I did about the DC-3?

Weeks later, standing in the cockpit behind Capt. Mosquera, finally passing through the dark curtain of clouds, the plane suddenly catapulted hundreds of feet heavenward, thrown aloft by the thermal updraft drawing moisture from the jungle and billowing it, and all of us, toward the stratosphere.

My heart swelled. This felt like what I live for. Behind me, other passengers, sitting shoulder to shoulder, clutched the bench below them.

The first time I saw a DC-3 was in Beira, Mozambique in 2019. It belonged to Samaritan’s Purse, an evangelical group delivering food to people made homeless by Cyclone Idai, the aftermath of which I was reporting on. Many of those people were in incredibly remote areas, but the DC-3 could take off and land on makeshift landing strips or even barren fields while laden with 7,000 pounds of cargo — double as much as a Cessna Grand Caravan.

That combination made it advantageous in this and other humanitarian situations. It is also what made them a decisive factor in the Allied victory in World War II, when the vast majority were produced. DC-3s ferried troops and airdropped supplies throughout the war, from Belgium to Burma.

That the DC-3 still flies eight decades after its heyday also speaks to its durability. This is the kind of plane that can be put back together when its nose gets dented or a hard landing rips off a wheel. The one used by Aerolíneas del Llano crash-landed in 1973, seventeen years before I was born. According to an article in El Tiempo, a Colombian newspaper, the passengers were unscathed. The plane was hammered, literally, back into flying condition. Even now, the safety kit hanging in the cockpit consists only of an ax, a machete and a straw hat stained with engine oil.

I discovered the plane because one day I was absently checking an app I’m mildly addicted to, FlightRadar24, which shows real-time flight tracking information on a map. I tapped my finger on a plane flying in a sparsely populated part of the country and, to my surprise, it was a DC-3.

A couple of weeks later, I took a shared taxi from Bogotá through the Andes Mountains to the airline’s dimly lit office in Villavicencio, the largest city on Colombia’s llanos. I paid in cash and got a handwritten boarding pass.

If you’re a fisherman, you might pay for a flight in salted fish. Farmers have used cacao as currency. It’s no big hassle to the airline’s owners — they resell the goods at the wholesale market in Villavicencio.

As dawn broke on what would be the first of three days I spent flying in the DC-3, Leonardo Rivera, whose family contracts the plane for weekly flights to secluded communities in the Amazon, leaned against burlap sacks of dried fish.

“Bagre apuy, bagre tigre, cachama,” he said, listing kinds of riverfish. “As good as money.”

The passengers were mostly people who are Indigenous to Colombia’s plains and rainforest or tradespeople who’ve settled in those frontier areas. Many from both groups spoke about the “settlement” of the region still being underway, usually as a good thing. Many villages don’t have doctors or any government services beyond ramshackle schools. Very few can be reached over land.

A typical landing strip in Colombia’s vast eastern regions is made of dirt and can be as short as 350 meters. Or, put differently, seven and a half times shorter than the shortest runway at New York’s J.F.K.

Germán Romero, who flew DC-3s in Colombia for 47 years before retiring in 2023, recalled transporting not just medicine, but iceboxes, mattresses and the outboard motors that locals affixed to their wooden canoes.

“The jungle has been settled piece by piece,” he said. “For many years, that has mostly been by the occasional barge and the DC-3s.”

It took very little time to realize that what had been a nerdy novelty for me was a necessity for people in the country’s remotest communities.

As we rattled down the runway, Francy Mosquera, no relation to the captain, covered her ears with her hands and closed her eyes.

“I’m terrified of this,” she said. But she had little choice.

Ms. Mosquera, 36, was a teacher from the city who had been reassigned by the government to a newly built school in an Indigenous community called Pueblo Nuevo, an hour upriver from Barrancominas. In this town, our flight would make its first stop. It would have taken her at least three days to get there by boat.

She carried little, no more than a backpack and a small, black duffel. She knew no one in the area. When I bade her farewell on the dirt landing strip in Barrancominas, she looked paralyzed.

“Well, here we are,” she said, looking at the smattering of buildings and the muddy Guaviare River. “I haven’t the faintest idea where I’m going.”

We had more stops to make, and the afternoon clouds were getting tall and dark. The captain beckoned back the passengers who milled about, stretching their legs. They clambered in and squeezed onto the long bench in the plane’s hold, which can fit, at most, 19 average-sized people on it. Across from them, tied down with ropes, was an assortment of cargo, some typical, some unusual, but all indicative of the plane’s role in that slow but ongoing “settlement.”

There was a box of Starlink internet receivers. There was tin sheeting. There were two female mannequins with enormous butts. And there were three marble chairs addressed to Monsignor Joselito Carreño Quiñones.

When we tracked him down in the town of Inírida, where he is a vicar, he explained why he had spent a couple thousand dollars of his church’s savings to fly out the heavy chairs.

“It is a way to convey the beauty of God’s creation to our growing parish,” he said. “You don’t have to paint it. It expresses its own God-given beauty.”

As we rolled for takeoff, the plane hadn’t even reached 100 miles per hour when it began to levitate, clearing the trees just in time.

When the DC-3 was introduced in 1936 by Douglas, an American company, it immediately revolutionized air travel. Aboard it, one could get from New York to Los Angeles in just 18 hours — with only three stops — fast enough to convince many people to trade railways for airways. That kicked off the commercial aviation era we have lived in ever since. By 1939, 90 percent of all flights worldwide were on DC-3s.

Several hundred entered passenger service, but ten thousand more were made for the war, which began shortly after their debut. Most were put together in California by the famous Rosie the Riveters, women who joined the war effort on industrial assembly lines. Nearly 5,000 were produced in 1944 alone. The then-U.S.-allied Soviets, who had been granted a U.S. government license to build their own variant of the DC-3, built 5,000 more.

“I can feel that this plane was made by women,” Capt. Mosquera said one day during a short stopover in Barrancominas. He flashed a characteristic grin; he has a flirtatious energy in much of what he does. “I cannot be brusque with this plane. It requires you to treat it softly,” he said.

All planes are machines with switches and buttons and levers, but the DC-3 is from an era before autopilot, and flying it requires constant attention and finessing of various dials, the occasional pulling of latches and the monitoring of many this-and-that-o-meters.

According to the Air Force Research Agency, Aerolíneas del Llano’s aircraft began its life with the U.S. Air Force on April 17, 1942. After the war, a U.S. government agency called the Reconstruction Finance Corporation sold thousands of DC-3s into commercial service.

Vast fleets ended up in developing countries with only the barest infrastructure. According to Alexandre Avrane, who runs AeroTransport Data Bank, the world’s most extensive collection of aircraft history, the plane first went to the Texas-based Lone Star Air Cargo, then Brazil, and finally to Colombia.

At the time, most people thought that DC-3s would be replaced by the more advanced planes rapidly becoming available, like Douglas’s DC-6 or the Boeing 307 Stratoliner, which had pressurized cabins and could fly over the weather, reducing turbulence.

American Airlines retired its last DC-3 in 1949. An article in the Times from that year said that while the DC-3 had been “one of the greatest passenger planes ever built,” it would soon be “as obsolete as the fringed surrey.” (A fringed surrey being a horse-drawn passenger carriage with a frilly canopy.)

But what will finally extinguish the run of this last passenger DC-3, however, isn’t a better plane, or a lack of spare parts, or even another crash, but insurance agents who don’t seem to feel any of the plane’s romance. Aerolíneas del Llano is fighting with its current insurers as they continue to inch their rate upward toward the bounds of affordability.

For now, though, the people of Colombia’s llanos rely on the DC-3 to make modern life a little less distant. On my second day of flying, someone was expecting the plane to deliver a birthday cake. Someone else awaited a bottle of Buchanan’s Deluxe whiskey.

The cargo hold was stuffed. That day, a sampling of what it contained included 10 boxes each with 100 live baby chicks (all chirping excitedly), dozens of grown hens, two cockfighting roosters, iron rods, and sacks of potatoes and onions. Passengers were returning from doctor’s appointments, or essential errands like cashing pension checks at the bank in Villavicencio.

While I stood on the tarmac in the dawn’s calm, I had thought all the cargo for the day was in order — a tableau of rural miscellany on a dilapidated trolley — and then a van from a funeral parlor pulled up.

Its driver opened the back door and carried out a coffin wrapped in black plastic. It was about a foot and a half long.

Capt. Mosquera tilted his head knowingly. “We see that a lot,” he said.

Nicodemus León, a two-year-old from a community called Siare, had fallen severely ill and been brought to Villavicencio weeks earlier but didn’t survive.

When we landed in Barrancominas, we expected to find baby Nicodemus’s mother waiting, but she was still on her way from Siare, eight hours away by boat. Siare has no cell reception, internet or any other reliable means of long-distance communication.

We left the coffin on a tarp on the airstrip, next to boxes of dried goods, and flew on.

At our next stop, a red-dirt outpost called Cumaribo, we picked up a severely ill 20-month-old and her mother, and I felt as if I were seeing Nico’s story play out, just at an earlier stage.

Ana Gabriela Martínez, 22, and Cloe were leaving their Indigenous reserve for the first time. Over the roar of the DC-3’s engines, Ms. Martínez explained that every time Cloe cried, she fainted. To reliably resuscitate her, she could press on Cloe’s right side and lift her right arm. Doctors who visited the reserve recently had told her that Cloe had been born with a heart murmur and that an operation in Villavicencio might be the only way to save her.

Capt. Mosquera flew low and steady with the windows open, letting the humid air rush through the plane.

Simón Posada contributed reporting.