I come back often to the green river in daydreams, the river as I knew it when I was 15 years old and my stepbrother Eric was still alive and captain of our unlucky crew of three. I think of the long days of June on the river, the 500 miles of it that carried us for almost a month from the border of Wyoming through Colorado through red-rock Utah. I remember how when we beached at the one or two outposts along the way, little Indian villages with just a bridge over the river and a few trailer homes and no phone, I'd look at myself in a bathroom mirror and be astonished at the burnt-brown, wild-haired boy staring back, who had muscles that hadn't been there in New York, who had no idea what day or date it was. That's when I knew I wanted to live forever on a boat in the desert with my stepbrother and his oldest friend, Rob, like the three loneliest, most primitive men, finding the shelter of the cottonwoods as we lay down to sleep in the sand, and in the mornings, fearful and hopeful, finding again a safe path down the raging chutes of water.

And then, of course, I think of the accident and what I did to ruin our trip. Sometimes I wonder how we even made it home after that. I think of how we rowed and rowed with no way out but down through the most violent of the rapids, and then on Lake Powell, in the darkness of the new moon, racing against the injury, and Eric cursing my stupidity. In the end it was the only river we would ever run together. And so it's the Green River I come back to, in daydreams, hoping this time to get it right.

The Green River is one of the epic drainages of the west, a river of the beaver trade, a watering place for rustlers, a landmark and compass point for early Spanish explorers, and a hideout for Butch Cassidy. Dropping 9,000 feet from the Wind River Range to its confluence with the Colorado, the Green was first explored at length by a one-armed ex-Union Army major named John Wesley Powell, who in 1869 embarked with a crew of nine oddballs in rickety boats of pine and oak. Powell emerged from the canyons 99 days later, half-starved, short two of his boats and four of his men, having kept a log that was eventually published as the rollicking bestseller 'Canyons of the Colorado'. It was Eric's dog-eared, mud-wet copy that had inspired and would guide our trip.

On June 22, 1988, Eric, Rob Morris, and I entered the Green under the shadow of Flaming Gorge Dam. Unlike Powell, we had the benefit of inflatable rubber. Our raft was a 15' x 7' Maravia, with an oar station at its middle and storage front and aft that burst with the necessities: bread, ham, cheese, cans of beans, tuna, beer (Eric drank gargantuan amounts of beer), an ounce of marijuana, psilocybin mushrooms, several tabs of LSD, a tent, sleeping bags, a first-aid kit, grill, pan, and gas stove, plus Eric's red Prijon T-Canyon kayak, all 11 feet of it strapped to the stern, the baby on the mother's back.

The river gathered us to its fast lane, the sun blazed, and on that first and second day it was smooth cruising on riffles. I smoked pot and lazed and watched the blue sky and white rock and the silt of the water. On the third day, the rock turned the color of blood, the walls rose up 2,000 feet, as if clicked on, and the river plunged into "a great stone mouth," as an early trapper described it. Powell and his crew named this passage the Gates of Lodore, and he worried at the unknown beyond. The sound of rushing that came from the gates made them seem like "a dark portal to a region of gloom," he wrote. "The old mountaineers tell us that it cannot be run."

Our raft lifted like a cat getting kicked, and here for the first time I knew there was no turning back, even as I literally turned back to watch the canyon rims disappear). The spray nettled the eyes, and from the top of a wave we saw sky and rock and the calamity of more rapids below; everywhere there was rushing, roaring, echoing (a sound that at night in Lodore never stops – it could drive you crazy). The water formed pillars, toppled, filled our raft with hisses, explosions, Eric tearing at the river with his long thin arms. On his face there'd be a smile, white and toothy and a little power-maddened, and from this long-distance stare, reading the hydraulics and eddies downstream, he would cast an eye on me and yell, "Don't fucking sit there, stupid – bail!"

Eric soon regretted my existence: I didn't stow gear correctly, I was lazy, I ignored orders, disappeared up canyons writing poetry, all of which, Eric felt, made me a waste to have around. The way I rowed was wasteful. I even made wasteful sandwiches. "They fall apart," he said.

Four days into the trip, while we were still in the Canyon of Lodore, I got heatstroke during a rare calm stretch. I was high on something good, and Eric and Rob turned a fantastic shade of purple and disappeared. I had passed out, which, in Eric's eyes, pretty much blew away my other offenses.

He tossed my body over the side and tethered my life jacket to the boat. When an hour later I woke up trembling in the icy water, he said, "You woke up. There's no luck in this world. Hey, Chris, I'm thinking you don't give a shit about the boat or the river or me." I noticed he had placed a big droopy straw hat on my head. Rob looked at me with pity while Eric went on. "I tell you to wear a hat. You don't listen. Now look at you. We hear a rapid coming up. I tell you to secure your shit. You don't even know where your shit is. And I'm starting to think I shouldn't have brought you. Because who needs a fuck-up in the wilderness?"

I met Eric Konheim during the collapse of both of our families, when he was 17 and I was seven. My father and his mother had come together after divorces that seemed to us speechlessly tragic (and that our parents, by contrast, thought quite amicable). I stayed weekends in Manhattan, in the enormous apartment where Eric and his brother, Alex, had grown up, and I remember one night sleeping on a pull-out couch, in the living room, and waking to see a shadow, tall and lanky and long-haired, flipping channels in the blue glow of the television and cursing, shaking its head.

The summer I was 9, Eric came to stay on Nantucket, where our parents had rented a house on the beach. He was wild-eyed with hair to his waist, and brought his beautiful big-breasted girlfriend, Paula Rosenfeld, both of them shouldering overstuffed backpacks. One day the preppies in town mocked him for being a hippie, and he flew back home in a rage; he apparently hated being lumped in with what he considered a wasteful subculture almost as much as he hated preppies. He disappeared into the bathroom, and I heard a bashing of the wall and a roar of invective that ended with a great big "Fuck it!" followed by three hours of silence, with Paula crying at the locked door, thinking he was killing himself.

When he emerged, covered in clumps of hair, he wore a crew cut he'd butchered with a pair of nail scissors. "There," he said. "So everyone can fuck off now."

That was Eric, the angriest guy I'd ever met, though it would take me a long time to figure out what really was bothering him. Paula, who years later became a psychotherapist, remembers that "there was a famous story of him getting in a fight with some bikers. Once when we were in his van he hydroplaned and we spun around and around and almost died. These moments were like his trophies."

I'd guess that a lot of this anger came from the flame-out of his parents' marriage. But somehow the stakes with Eric seemed higher. (I too had seen a divorce, and it broke my heart, and then I went and got stoned in my room.) Eric told Rob Morris that the divorce, as he saw it, was the last gasp of what he called "the big lie," the lie that the family unit was sacrosanct and unbreakable. This realization, bitter as it had to be, was also the dawning in Eric of a kind of politics of how to deal with the world. "We're constantly being misled, constantly being lied to," he told Rob. His father, Bud Konheim, was the business brains behind the Nicole Miller fashion house; his mother, Carolyn, was a pioneering environmentalist, and helped found Citizens for Clean Air, the country's first clean air advocacy group (inspired when one day she saw soot on infant Eric's face). Their split seemed to tear Eric in opposing directions: He claimed to want worldly success – to succeed the way his father had, by his own hands – but it would have to be with his mother's values, something not measured in money, for money-love, after all, was another "big lie."

So by the time he was 16, Eric had already been arrested protesting nuclear power plants in the Northeast. At 21, he ran his first river, the Colorado through the Grand Canyon, and henceforth dedicated himself not only to saving the wilderness but also to experiencing it for himself. At school he studied architecture and urban planning – he believed passionately in cities – but found the education useless for running rivers, so instead of desk-surfing he started a one-man moving outfit in Manhattan: "Man with Van." Six months of the year, he labored out of his Econoline 350, in army surplus fatigues and $3 high-tops, endlessly looping Frank Zappa and Pink Floyd, eating canned beans and drinking forties of the crappiest malt liquor, saving up for the other six months. "There was nothing frivolous, nothing in his life that didn't have a purpose," his roommate of three years, Debora Doell, told me. "Eating out was frivolous. Not re-using an envelope was frivolous. Having nice clothes was extremely frivolous."

Doell, a native of Oregon, shared Eric's Lower East Side apartment, helping fight the rats and the heroin addicts upstairs, whose stopped toilet leaked brown through the ceiling. She told me that Eric frequently got in screaming matches with people he saw littering. Although he loved New York, he hated that it was an epicenter of the materialism and bloated self-regard that he thought in the end would destroy the planet.

The rest of the year he kayaked. He paddled the Sea of Cortés in the company of whales, was chased by alligators in the Everglades, and ran the whitewater of this country's last wild rivers: the Snake and Salmon in Idaho, the John in Alaska, the Klamath in Oregon, the Ocoee in Tennessee. In the Southwest, where already by the 1980s the Sunbelt had begun its thirsty sprawl across the desert, he ran the San Juan River from New Mexico into Utah, where he fell in love with the spartan land, its terrible balance of water and rock. In between, he moved people's furniture and volunteered at a recycling program in his neighborhood and thought how in his life he would one day save the rivers from development, not knowing how or where to start.

When Lodore and its sister canyons in Dinosaur National Monument finally spit us into the vast arid open country of the Uinta Basin, the river ran wide and shallow for almost a hundred miles, and for the first time we scraped gravel and had to get out and shove. The unwalled, unconfined sky came as a shock. Some days the sun smashed the world, we could barely breathe, and we longed for rapids. The thermal winds blew at 40 mph, turning our boat and deviling the dust over the water. Rain fell from boiling clouds that disappeared 10 minutes later, but in answer the mud and cottonwood groves filled with mosquitoes that beat on our arms and drew blood. "The mosquitoes fairly screamed," wrote a member of Powell's crew back in 1869. "One of the men says that while out on the shore....a mosquito asked him for his pipe, knife, and tobacco and told him to hunt his old clothes for a match."

One night we watched an electrical storm, a blue and white spider strutting and flashing across the darkened sky. Then it was upon us fast, keening, and fired a bolt into a huddle of trees. A fire started in white, burnt out in red, the rain clattered, the lightning splashed in the mirroring water, and the three of us squatted on our haunches under a sandstone ledge: three hominids nearly holding one another, shoeless, silent, cowering from the storm.Five days later, the tribe was at one another's throats. I may have been a stoner and an acidhead, but Eric liked to drink, and when he drank he got mean. He taunted Rob, the kindest among us. Rob had a pensive streak, he was sometimes melancholy and unspeaking – not the exclamatory man of action that Eric was. For this failing – that Rob was not, in the end, Eric – there were jokes and mockery, but amends could be made. As for me, I was simply to be dumped at the next town: "You just....get a bus. Get back to the airport. Get the fuck off my river."

Finally Rob spoke up. "Eric, why are you always so pissed off? I mean, what's your problem with yourself that you have to attack people all the time? Why can't you ever just be....happy with things as they are?"

Eric drank more and said nothing for a long while, which somehow was worse. One night, in my sleep I hugged him through my sleeping bag and held him tight enough that he awoke and untangled himself, and the next day made fun of me – "He's a fag, huh, Rob?" – shrewdly dividing his crew.

But a little farther on there was another change, never spoken, but understood. Rob and I at last were allowed to pilot alone, Eric flying at our side in his kayak, beating out the rhythm of the descent with his calls. "Cut left – big hole....What the fuck are you fucking doing?! That's it, perfect!" Thanks to the wisdom he shared, his crew was learning the water – about standing waves and curlers and how to find the channel and stay calm.

After particularly gruesome rapids where he'd have to take the oars himself, Eric would ground the raft and with a criminal grin untie the kayak and portage it back upriver along the slickrock. Once in Desolation Canyon he ran the same crazy stretch again and again, his kayak's dance appearing initially quite out of control. Then I realized it was a dance: It was measured, had steps, coaxed the water to him like a partner, and when Eric's hips snapped the kayak kicked and flitted. In its turmoil and concentration it was a beautiful dance, the only one that Eric could do.

On the 14th or 15th of July, in Stillwater Canyon, where the water runs narrow between soaring rock, I pulled what has to be the dumbest move in the 275-million-year history of the place. We were cliff-jumping; we cliff-jumped all along the river, testing the depths with an oar or swimming down into the brown darkness beforehand. Eric was siesta-ing under the shade of a tarp we'd fashioned on tent poles over the stern, so Rob and I were on our own. I splashed to the foot of the cliff and started climbing, and Rob probed.

"Too shallow," he shouted, poking an oar. "Come on down."

Edgar Allan Poe wrote a story called "The Imp of the Perverse," which describes by turns an imp that rests and wrestles inside us all, a compulsively self-destructive creature who bids us to do exactly what we know is the worst thing to do. So the imp and I jumped. Into what turned out to be three feet of water. From 20 feet up. There was a sickened hollow mewling that echoed off the walls, and Eric shot awake in the raft that had by then drifted down stream. I tried to stand up and fell back in the water like junk.

"Chris, I told you not to jump!" screamed Rob.

"I think – my leg – it's – broken." Now I was crying.

I floated to the boat and they hauled me in and examined the swelling left leg. The flesh around the tibia was turning an odd yellow and I had trouble moving my toes. "I don't fucking believe this," Eric said, and for a moment he was at a loss for words, the first time I'd ever seen it. "Yep," he finally nodded, "you're an asshole. That's all I have to say. Rob tells you not to jump, it's too shallow. And you jump." After a moment, Eric very quietly said, "I'll never forgive you for this."

We paddled to the shore and gathered wood and Eric tied a splint with old rope and rags, and we each took a moment to absorb what lay before us. Enclosed by walls 1,200 feet high and rising, we had no choice but to continue downriver to Lake Powell, five days south, and we hadn't yet arrived at the most dangerous stretch, where in Cataract Canyon the Green is engorged by its confluence with the muddy Colorado.

The next few days were a blur of pain minimally dulled by our fast-diminishing weed. One evening, as Cataract drew closer, my broken leg and I went to take a shit, which had come to be a maneuver like docking a truck. Eric had always lectured us about crapping near the river, so I propped an oar under my shoulder and hopped far into a lonely grove of cottonwoods and high yellow grass. I remember the comedy of keeping the broken leg straight and unweighted while squatting with the other one; I remember teetering on my oar, trying to maintain a little dignity; I remember falling in my own crap, which was steaming in the cooling afternoon, with the sun dipping below the canyon rim. I wanted to cry, but instead I just lay there awhile looking up at the walls and feeling suddenly calm and thinking that my death would mean nothing here, that it would be but a speck in the vastness of geologic time. And this was not, for some reason, a frightening thought; maybe it was a dawning, a revelation, who knows? But it's stayed with me.

When Cataract's walls closed in, Powell's men remembered Lodore and they groaned. For our part, we beached on an open strand and spent our most sullen night on the river, not even pitching a tent, and then in the morning, unable to stomach breakfast, we ran Cataract in one fell shot.

I remember the first rapids racing to us like a car crash, and Rob yelling atop the wind, "Keep your legs forward if we go over – don't let your head go downstream!"

"Oh, for fuck's sake, we're not gonna flip," Eric declared, and no one said another word, for we were now in the mosh of waves. The boat shuddered, I clung, my leg shook and went white-hot, and almost immediately I bounced in the air and was scudding overboard. The wall of water smashed my face and was about to tow me under when a pair of arms snatched me from behind and – to this day I'm not sure how Rob did it – pinned me to the raft, all while gently cradling the leg.

In Mile-Long Rapid, Eric nearly had to eat his words. The bow pointed skyward, a great cry went up from the three of us, and the water appeared to slow down as if envisioned in a fugue state: You could watch the holes gape and the waves curl, taking their time to come at us. And I turned my head and saw Eric pounding at the oars, and now he wasn't smiling. Then, as suddenly as being dropped into another dream, we were in the Big Drops and Satan's Gut and Capsize Rapid – Cataract's two dozen rapids average more than a half-mile each over 50 ridiculous miles – and there was no other existence but howling water and spray and pain.

Cataract Canyon ends as abruptly as it begins, and we only realized we'd made it alive when Eric said, "The current – look...." I pulled myself up from the flooded boat bottom, Rob stopped bailing, and we looked down the canyons, and knew immediately we were on Lake Powell. We laughed and high-fived, and yet also knew that 33 miles of dead water stood between us and the road out at Hite Marina.July 20 marked the new moon. We paddled through the night, spelling each other at four-hour intervals, with only the tops of the cliffs lit by the stars. I was allowed to smoke our last joint, and the only sounds were the plashing of the oar, the boat whispering over the water, and, once, a giant bird beating its wings with a thumping like a distant drum. Eric had no love for the lake, this ill-chosen monument to the explorer. Once there'd been a canyon here that Powell and his men, terrorized by Cataract, found so delightful in its pink cathedrals and green gardens they called it Glen Canyon. But Glen Canyon Dam, erected to produce electricity for the strip malls and air conditioners of Phoenix and Las Vegas, had drowned those marvels 20 years earlier. "A fucking tragedy," Eric proclaimed.

Finally, arriving at Hite, no one to greet us, maybe three forlorn boats tied at the docks, and a Park Service outpost baking in the 110-degree heat. A lone ranger stepped from his shack, peeled back my splint, and said, "Yuh, it's broke." We had arranged for a friend to meet us with the Econoline, driving it down from Flaming Gorge, but in the hurry to save my leg we'd emerged four days early. The ranger, who looked to be nearly as stranded as we were, offered to call in a helicopter at $100 a mile. "No money," Eric said, and instead we left Rob with the raft and set out under the white sun to hitchhike the hundred miles to the nearest county hospital.

It took us three rides, more than seven hours, Eric hoisting me in and out of the beds of pickups. The sun was terrifying, it was everywhere; I understood now how men died from the heat without realizing they were dying. We drank our two gallons of water, and ate our last six strands of beef jerky, and I, with an old oar for a crutch, floated in the shallows of consciousness, borne by the sheer will and brute anger of my brother.

The following year, in 1989, just short of his 26th birthday, Eric wrote a will witnessed by his roommate, Debora. He bequeathed most of his savings – tens of thousands of dollars, the harvest of his frugality – to the Rocky Mountain Institute, a nonprofit that works on water preservation. The two of them lit up a bowl and laughed and laughed as they each signed the document.

A few months afterward, it wasn't so funny. Solo-kayaking 350 miles along the rocky coast of Venezuela, Eric ran into a storm. Of the Venezuela trip, Eric wrote simply, "Big surf. Strong winds. Broke kayak." This was classic Eric understatement. He paddled all night to keep from being driven out to sea, and some time the next day – he hardly remembered how – he came to a white sand beach and collapsed. Later, he spent several nights in jail. The country was locked down after a series of bloody riots had claimed 300 lives; people had been shot in the streets, and Eric was caught walking on the road past curfew. Eventually he convinced a lazy guard to let him leap from the back of a truck that was transferring him to another jail, and he hid among garbage cans until dawn.

After Venezuela I think Eric began to ponder the wisdom of his path. He envisioned himself as a catalyst of some kind of social change, but he wasn't finding his footing. He was in love with a woman he'd tracked down after seeing her interviewed on TV about sailing around the world alone at age 18. But she was soon to be married and, though they became close friends, he didn't dare ask her to leave her fiancé. He thought about applying to architecture school, but the notion of sitting in a classroom drove him back to the kayak. He spent a lot of time thinking about the precarious state of the rivers he ran, and the metastasizing cities that always needed more from them. John Powell, who after the Green spent 13 embattled years as head of the U.S. Geological Survey, had warned Congress that the inevitable result of the pace of settlement in the west would be the drying up of its most precious resource. It pained Eric to see, even a century later, how few people beyond his river-rat friends, some Rocky Mountain Institute scientists, and local ranchers seemed to care. And yet, neither could he figure out how to carry Powell's torch in a way that didn't strike him as small-time. He didn't want to hand out flyers; he wanted to change the world. Two years before he died, he told a friend: "I don't want to lead a pathetic little life."In June of 1991, Eric headed west the same as every summer to run new rivers. In the days before he left New York, he threw a party with a keg of beer iced in the bathtub of his crummy apartment. But he'd been too busy to telephone the invitations. Debora was in Oregon visiting her family, just a handful of people showed up, and Rob Morris was the only guest who stayed for long. Eric got drunk, and Rob listened as he talked. Near daybreak Eric broke down in tears, said he was afraid he'd never see Rob again, and threw his arms around his friend. "Uh, Eric," Rob said. "C'mon, you've gone on these trips a million times. You're not gonna die."

By the time he hit Oregon, Eric seemed in better spirits. For a few days he stayed with Debora. But when he told her goodbye, he took her in his arms, too, and whispered: "This is it. I think this is the one." Debora just thought it a joke and laughed and kissed him on the cheek.

From Portland he headed south, hitting Eugene and Springfield, where after years as a rogue on the water he finally took a class to qualify as a whitewater guide. The instructors concluded that Eric was among the best young boatmen they had seen, which so delighted him that he phoned his mother to tell her. Then he went to celebrate by surf kayaking the infamous waters of Coos Bay, on the Oregon coast. Two rivers run from the mountains into the bay, creating a havoc of currents and violent "sneaker waves," which come up silently, often from the opposite direction of the incoming swells a surf kayaker hopes to ride. Eric was eager to test himself against the bay's traps.

On June 12, 1991, at around 4 pm, Eric paddled in his T-Canyon, the same kayak we had carried with us on the Green, into the heavy-running 50-degree surf. He wore a helmet, whistle, shorts, synchilla shirt, and life jacket, but no dry suit. It was to have been a short run, over in time for dinner.

By late afternoon three other swimmers and boaters had drowned during what turned out to be one of Coos Bay's deadlier days. At 5 p.m., the T-Canyon was found rocking out beyond the breaks. That night divers in a helicopter search discovered Eric's body floating facedown 150 yards offshore. "Asphyxia by drowning, immersion hypothermia," read the medical report, noting that his core temperature was 73 degrees. His mother, Carolyn, has long speculated that a sneaker wave snapped his oar into his head and knocked him out; the autopsy found a large bruise on his forehead.

A few months ago, I sat with Carolyn, my father, and Rob Morris, who is now 42, the same age that Eric would be today, and we watched a film that Rob took of our trip with a Super 8 camera. The footage was raw and jumpy and without sound. Waves like coffee boiled up, burped, hit the lens. There was a shot of me looking pale, with Eric standing behind, watching downriver, tanned as a panther. Cut to a shot of our yellow waterproof cassette player (probably blaring the Dire Straits album Brothers in Arms). A heron walked the water and took wing. A wild horse, white, with silver mane, drinking. Cut to Eric in his kayak shattering through brown foam, the camera not keeping up. "He was such a good-looking guy," said Carolyn, with tears at seeing her son. She hadn't watched the film in 15 years.

I don't believe in God or an afterlife, but for a long while after his death I foolishly imagined Eric was watching to see what happened to the 15-year-old in these reels. In my 20s I wasted a lot of time, writing poetry that never got published, dead-ending in jobs that taught me little. I returned out west a lot, backpacking the canyonlands that Eric opened to me. Then I became a journalist and was, in a sense, saved: I found what Eric didn't.

Only recently did I realize that it is easier to replay old films of old roles than to face the fact that none of us who were close to Eric did a very good job watching him. At the time he died I think he knew his adventures were reaching some sort of endgame. Paula Rosenfeld, who calls Eric "my first love," who has recurring dreams of him being alive, says, "If it didn't happen that day, it would've happened some other day. I think unconsciously he was trying to kill himself his whole life. He wanted to be bold. He wanted to be strong. But he didn't want to look inside. I don't think Eric knew that he was already the person he was looking for." Perhaps in his emotional partings from Rob and Debora he was asking for somebody to pull him out of the water. If so, no one, not Rob, not Debora, not Paula, not his environmentalist mother, not his rich father, not his horrible little stepbrother whose leg he saved, did.

The last time I saw Eric, three weeks before he drowned, we sat on a stoop in Brooklyn and he told me we should do another river soon. It shocked me the way he said it: almost shyly, like I was an equal or friend. But I was still scared of him and ashamed of what had happened on the Green, so I shrugged and said, "Yeah, another river'd be good," and that was that.

I didn't understand how sincere the offer was until a few months ago. I was reading the letters written of him after his death, the flood of letters that came in from girlfriends and whitewater buddies and recycling obsessives. So many of the notes said the same thing: Eric was a romantic, he wanted beauty and order, and when these failed, as they must, there was disappointment and then rage. "That's when I most worried about him," his college friend, Alessia Ortolani, wrote. Oddly, there was something of our trip down the Green that had lived up to the ideal. "He told me several times," Alessia wrote, "how proud he was of his little brother, Chris, for being so brave the time he broke his leg."

Christopher Ketcham has written for 'Harper's' and 'GQ.' This is his first feature for 'Men's Journal.'