On the final morning of a weeklong fly-fishing adventure to Patagonia last December, I finally found my white whale. In the preceding days, I had fished all manner of beautiful rivers and lakes and caught (and released) more than my share of fish. But I had yet to land anything truly special — a trip-maker — and this creature appeared to be just that.

My guide, an American expatriate named Monte Becker, his colleague, Hayden Dale, and I were on the Paloma River, a renowned trout stream in central Chile. We had begun the day by navigating a series of Class III rapids, then catching a handful of brown trout and rainbow trout that would have been considered whoppers on most other rivers, but here were just the latest in a series of ho-hum catches measuring 18 inches or more.

Just before lunchtime, we ran a stretch of white water that squeezed between a pair of enormous boulders, then opened into a small, hidden canyon. With its overhanging granite walls, moody light and silty water the color of sapphires (if the sapphires had somehow been electrified), the chamber bore traces of both the real-life Blue Lagoon and the fictional Middle-earth. It was one of the most striking spots I’ve seen, on or off a river.

For a time, we lingered there to fish, but with no luck. Then Becker rowed us downstream a few hundred feet to a small, unnamed island in the middle of the river, tied our inflatable raft to a tree stump, and instructed me to follow him to the top of a rock outcropping some 30 feet above the water. From that vantage point, we could see a near-perfect trout hideout: a pristine, ice-blue pool protected on its upstream side by the island, but still adjacent to the river’s main current and its ready supply of insect life.

Becker pointed to the head of the pool. “Good fish,” he said. “Rainbow.”

Sure enough, there was a large, dark slab rising and falling in the water column, rhythmically picking flies off the surface for its lunch. We put him at just under 20 inches.

A moment later, Becker said, “Look at the bottom of the pool. There’s another one there. A big brown.”

I scanned the area, but all I saw was an underwater log. Then the “log” rose to the surface and ate a fly. The object in question was, in fact, the largest trout I have ever seen outside of Instagram, easily 2 feet long, perhaps longer. This was exactly the sort of moment I had come to Patagonia for. Now all I had to do was get the leviathan in my net.

A storied destination

Extending across Argentina and Chile, Patagonia offers blue-ribbon angling on both sides of the border. I chose to fish on the Chilean side, in the Aysen region, near the city of Coyhaique. That area is known for its combination of rivers and lakes, and is generally less windy than other parts of Patagonia (wind is kryptonite to a fly-fisher). I planned my trip for December, the start of the South American summer, and booked a room at Magic Waters Patagonia, a full-service outfitter (guides included) just outside Coyhaique.

The hourlong drive from the nearest airport, in the city of Balmaceda, to the lodge, was like an episode of “Nature.” The Andes loom in the distance, their summits covered in snow, and impossibly clear rivers wind through valleys that stretch to the horizon in every direction. You could spend a lifetime just naming the shades of green. On the dirt road that leads to the lodge, we got stuck for a time behind a herd of cattle being driven to pasture by gauchos. “Patagonian traffic jam,” our shuttle driver said.

The lodge itself, a rustic-deluxe structure built from native lenga trees and river rocks, is tucked away in a small, verdant hollow with its own glacial lake. The owner and operator, Eduardo Barrueto, the son of a local teacher and angler, was guiding a wealthy client on the lake some years ago when the man asked Barrueto if he’d like to open a fly-fishing lodge there. Barrueto built the operation from scratch, eventually bought out his partner, and now runs the outfit with his wife, Consuelo Balboa, whom he met during a stint in culinary school.

The fish that got away

The next morning, with the sun out and the wind at a low roar, Barrueto and I drove to the Huemules River, named after a species of local deer that symbolizes Chileans’ love of the outdoors, and is featured on the country’s national shield. We waded into the river at a spot just below a small, postcard-perfect waterfall that made for a memorable introduction to the watershed. Within half an hour of working our way upstream, I had caught and released my first Patagonian fish, a healthy, 18-inch brown trout. Unlike North American browns, this specimen had a distinctive spearmint color perfectly suited to its surroundings. The adaptation was uncanny, a kind of natural-world magic trick.

We went on to catch perhaps 20 more fish that day, rarely going longer than half an hour without a strike. Most of the time we fished with a fly called a Cantaria beetle, a lure meant to imitate a large local terrestrial insect that Chilean fish key in on for its high calorie and protein values. The chance to fish with Cantaria beetles itself draws many anglers to Chile. Trout tend to attack the flies with uncommon aggression, making for particularly exciting takes.

Over the next four days, I fished every conceivable kind of water with remarkably consistent results. On Day 2, I fished the Simpson River with Becker and Dale, landing a variety of brown trout and rainbow trout and a particularly pretty 20-inch rainbow. More than once that day, Dale and I “doubled up,” or had fish on our lines at the same time.

On Day 3, Barrueto, Dale and I fished an equally productive section of the Paloma River in the morning, then moved on to Elizalde Lake in the afternoon. It was the first time I’d fly-fished on a lake. On my second cast, I caught a 20-inch rainbow; minutes later, Barrueto one-upped me with a 22-inch brown. On Day 4, on another section of the Simpson River, we found a group of rainbows in a hole beneath an elevated bank. We landed five of them in 15 minutes.

Day 5 was an especially memorable outing in which a group of us — myself, two other guests, our guides and a gaucho named Alfredo Medina whose family property abuts a section of the Mogotes River — rode horses to a stretch of that waterway. Fording the river on our mounts and clip-clopping along a narrow trail on the edge of a 40-foot cliff was an adventure in its own right. Lunch that day was a riverside picnic consisting of a whole, locally raised lamb roasted on a hand-carved spit over an open fire that Medina had prepared for the group. We washed it down with ice-cold cans of Escudo beer, a popular Chilean lager, that had been chilled in the river. It was like life imitating a beer commercial.

Then, on the morning of Day 6, Becker and I found ourselves perched above the Paloma River watching that big brown. “Go ahead,” Becker said. “Cast to him.”

My first shot fell short, the second too far to the left. But my third cast was on-target, and I watched as my fly floated toward its mark.

The next thing I saw was a gaping mouth break the surface, then snap shut on a Cantaria beetle. I lifted my rod and, improbably enough, I had him.

Although I didn’t know it at the time, Dale was filming a video of the scene on his smartphone. On it, you can hear Becker say, “Nice brown!” then scramble down the rock toward the water to net my catch. My rod is bent nearly in half.

“I can’t see him under the rock,” I say to Becker. “Tell me if he … “

The fish briefly surfaces, no more than 4 feet from the net. Then my rod straightens out, and I utter several of the seven words you can’t say on television (or print in this publication).

The fish is gone.

I have watched that video over and over again, deconstructing it as though it were the Zapruder film. Maybe I should have put more pressure on the fish. Or less. Maybe I should have raised my rod tip more. Or lowered it. Maybe I should have hopped up and down on my left foot and recited the Gettysburg Address. I’ll never know.

We ate lunch on the rock, where I tried to be positive. Despite losing that brown, I told myself, I had just spent a week enjoying some of the best fishing, meals, wine and company of my life. Still, I was miserable.

After we finished eating, Becker and I walked back to the edge of the rock and looked down at the river. The rainbow, the first of the two fish we had seen there, was back in his spot. I caught him with one cast, then released him. With a flick of his tail, he swam back into the turquoise depths, the sun glinting off his namesake markings.

To be a successful angler, it helps to have a short memory. Remarkably, I felt much better.

Jon Gluck is an editor and media consultant who writes frequently about fly-fishing.

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