WHILE WE MIGHT HAVE BEEN the first team to attempt a complete descent of the Djidji, we were hardly the first people to travel on it. Downstream of the put-in, we'd noticed old machete scars and bits of cord on some of the overhanging branches—an indication that workers from the logging camp had likely come this way in search of meat. Another good indication: On the floor of one of the abandoned cabins, we'd found a photo of a grinning Congolese worker holding a bloody pair of elephant tusks. And then there was the mysterious Joseph Okouyi, a Gabonese doctoral candidate studying red river hogs, who had recently established a research camp halfway down the Djidji, at the very center of Ivindo National Park, and who, in fact, had been scheduled to join us but dropped out at the last minute.

Curran was anxious to make it to Okouyi's camp by the end of day three—crucial timing, he figured, if we were going to make the train back to Libreville by week's end. But the log crossings were

This was it, and we all knew it: the primordial Djidji experience that White had been talking about. The canoes, the sweet-flowing river, the elephants' fissured gray flanks glistening like wet stone in the warm sun.

starting to take their toll, and we managed to rack up only nine over-the-ground miles before collapsing, exhausted, on a sandbar at dusk. Still, paddling in one of the green boats, I had seen my first elephant: just a glimpse of grimy tusks and an ancient gimlet eye staring out through leaves—but thrilling nonetheless. And I'd caught the biggest excitement of the day when an eight-foot crocodile came shooting out of the high grass and down a sandbank, heading directly for the canoe in front of me before diving beneath it at the last second.

About noon on the next day, we arrived at a place—a wide spot in the river—that felt somehow different. There was more sky, and shrubs instead of trees, and the banks of the river were littered with a mad profusion of tracks and dung, including gorilla and leopard, Starkey said. It was an obvious crossroads, and after we'd floated through it, he pulled over to the side and motioned for the rest of us to stop.

"The wind is in our favor right now," he said. "If we go back upstream and sit behind those trees, I think the chances are good we'll see something within the hour."

It was the perfect call. No sooner were we out of the boats and installed in our impromptu blind than two elephants materialized out of the brush about 50 yards downstream, a mother and a baby whose age Starkey estimated at one year. They stood on the bank for a moment, then swayingly moved into the river. The place was a "saline," Starkey explained; there was some kind of salt in the clay soil that the elephants loved. Rather than eat the soil, they sluiced a slurry of it back and forth in their trunks to extract its briny essence.

We crouched cautiously out of view at first, but when it became clear that the elephants couldn't see us, we stepped forward boldly, cameras snapping. A few minutes later, another mother and calf, this one about three, appeared and joined the first pair in the river, and then, perhaps more remarkably, the sun came out for the first time all week. Gnoundou took a canoe and paddled down to within about 20 yards of the grouping. The two cows looked up, sensing something, but then went back to their sluicing. Gnoundou waded in even closer, and Tehrani followed him, his camera out. "This is crazy," he said, glancing back at the rest of us and grinning from ear to ear.

This was it, and we all knew it: the primordial Djidji experience that White had been talking about. The canoes, the sweet-flowing river, the elephants' fissured gray flanks glistening like wet stone in the warm sun.

That afternoon, as the Djidji whisked us westward, we analyzed the tourist potential of what we'd already dubbed Plage des Éléphants ("Elephant Beach"). It was an obvious attraction within the park, a riverine version of Langoué Bai—the vast, grassy clearing in the southern part of the park that was famously frequented by elephants and gorillas. The first issue was how to get people there; the only alternative to three and a half days of log-hopping hell seemed to be a road. But of course a road would mean access for everybody—and everybody, Starkey pointed out, "means poachers."

At dusk we came upon a snag that had been chainsawed—a sure sign that we were approaching Okouyi's camp. I'd already conjured an image of the place in my mind: a small clearing by the side of the river with a few old canvas tents pitched beneath the limbs of some massive tree. Instead, we rounded a corner and beheld something truly shocking: a steep and completely clear-cut hillside littered with giant brush piles and the trunks of felled trees. Two wooden buildings had been erected and a third was under construction. Behind the first clearing was a second of similar size.

Curran was furious. Okouyi had "cut far more trees than he was supposed to," he said. Boyer was appalled. He'd imagined the camp as a potential site for one of John Gwynne's eco-lodges, but that seemed out of the question now—no tourist was going to come to the rainforest to look at a bunch of stumps.

No one was around, but the ashes in the firepit were still warm. I proposed that we camp there; it was late, Okouyi and his researchers would soon be returning, and we could get the full story. But no one else wanted to stay, so we shoved off and made camp a half-mile downstream. A short while later we heard a jarring sound—the whine of an outboard—and then a long dugout with six men in it came flying around the bend. Spotting our canoes, the helmsman cut the throttle and ducked behind a snag on the opposite bank, then pulled out a minute later and slowly approached.

It was indeed Okouyi's crew, returning from a day walking transects in the western end of the park, but Okouyi himself, they told us, was in Makokou on business. Curran nodded curtly. "Why did you cut down all those trees?" he asked. "You know this is a national park." The men stared blankly, not sure how to respond. "And what is the meaning of that second clearing behind the camp?"

"Plantation," one of the men said.

Curran shook his head disgustedly. "You tell Joseph . . ." He stopped, then went on. "You tell him we need to talk."