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 Mr. Barrueto if he'd like to open a fly-fishing lodge there. Mr. 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.
During the fishing season, the couple lives at the lodge with their children, Manuela, 13, and Martin, 10, their dogs, Blanca and Gauchito, and a house cat named Ruby (named for the Montana river, one of Mr. Barrueto's favorite places to fish). Meals are served at a large communal table, and the family and guests, only 12 at a time, typically eat together.
Guests are welcome to fish the lake as soon as they arrive, but because it was raining, cold and windy on the afternoon I checked in, I enjoyed a pisco sour in front of the fireplace and chatted with Mr. Barrueto about where we would fish during the week ahead. Dinner that night was an asado, or traditional Chilean barbecue, of beef ribs, rib eye and flank steaks, pork loin, chicken legs and local sausages, accompanied by boiled potatoes, a simple salad of lettuce, tomatoes and yellow bell peppers grown on a nearby farm, and several bottles of Marques de Casa Concha Grand Reserve, a Chilean cabernet sauvignon. Dessert was leche nevada, a classic Chilean sweet dish similar to a French floating island. Just about every meal was similarly fit for a gourmand lumberjack. By 10 p.m., I was in a deep, asado-induced sleep.
The next morning, with the sun out and the wind at a low roar, Mr. 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.
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 Mr. Becker and Mr. Dale, landing a variety of brown trout and rainbow trout and a particularly pretty 20-inch rainbow. More than once that day, Mr. Dale and I "doubled up," or had fish on our lines at the same time.
On Day 3, Mr. Barrueto, Mr. 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, Mr. 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 Mr. 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.
Although I didn't know it at the time, Mr. Dale was filming a video of the scene on his smartphone. On it, you can hear Mr. Becker say, "Nice brown!" then scramble down the rock toward the water to net my catch. My rod is bent nearly in half.
The fish briefly surfaces, no more than four 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).
After we finished eating, Mr. 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.
Chimalfe Patagonia Lodge, Lago Yelcho Puerto Cardenas, Chaiten, Chile; chimalfepatagonialodge.com; six-day, seven-night packages, food, lodging and fishing included, from $5,300.
Jon Gluck is an editor and media consultant who writes frequently about fly-fishing.