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Chasing Brown Trout in Patagonia's Cwm Hyfryd (Beautiful Valley)

How two Montana boys fished in the footsteps of Welsh settlers.

Chasing Brown Trout in Patagonia's Cwm Hyfryd (Beautiful Valley)

(Isaias Miciu Nicolaevici photo)

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In 1862, Welsh nationalist Michael D. Jones met in Buenos Aires with Argentina’s Interior Minster and proposed the idea of a new “little Wales beyond Wales” where Welsh language and culture would be free from foreign domination. The Argentina government gave him 100 square miles of land in the Chubut River Valley in Eastern Patagonia, and in 1865 the first 153 Welsh settlers arrived aboard the clipper Mimosa. Few of them were farmers, and although they had been told the region was similar to lowland Wales, the land near the Atlantic ocean was actually an arid semi-desert that provided poor crops and lacked water.

In a scene that seemed to repeat itself across the Americas, the native Tehuelche people helped many of the Welsh settlers avoid starvation. In 1885, the struggling immigrants arranged an expedition to head west toward the Andes, and in November they reached a fertile gap in the mountains they named Cwm Hyfryd (Beautiful Valley). Here, there were giant trees for buildings, grassy steppes for cattle and sheep, fertile soil for crops, and an enormous amount of fresh water coming from the snow-covered peaks. They planted wheat, and the town of Trevelin (from Trefelin, Welsh for “mill town”) was established in 1891 when the first flour mill in Patagonia was built there. Today it is home to the only bilingual Welsh/Spanish school in the world, and is famous for its Welsh tea rooms, black cakes, fields of tulips . . . and for trout.

An old timey image of a Welsh nationalist with a photo of a ship inset in the lower right.
Michael D. Jones, Welsh Nationalist, pictured in traditional Welsh and Patagonian attire. Also pictured is the clipper Mimosa that carried Welsh emigrants to Argentina. Photo of Michael D. Jones was restored (On Saturday 17 September, 2022) by Welsh artist, Rhyn Williams. Mimosa drawing by unknown artist - Museo del Desembarco, Puerto Madryn.

Fishing Frontier

Like the Welsh immigrants who first came to Trevelin, Rance Rathie and Travis Smith left their home country looking for greener pastures. They grew up as friends in Sheridan, Montana, where Rathie’s father and grandfather were both fishing guides. Smith grew up on a ranch along the Ruby River. They both hoped to be fishing guides, but Montana in the late 1990s was a difficult place to get started. Ranch gates were already locked, private land was leased for fishing access, and lodges were filled to capacity in nearly every major watershed. On some famous rivers, the rod days for outfitters were completely allocated. The only way they could be Montana guides was to work as contractors for those who already owned the rod days.

They soon decided they needed more rivers to roam, greater opportunity, and more space for adventure. They packed up their fishing gear, and headed to Patagonia to get their first taste at a whole new region that was opening up to fly fishing.

The area around Trevelin was mostly unknown to American fly fishers at the time, and Rathie and Smith became guides at what was then known as Trevelin Lodge for the 1999/2000 and the 2000/2001 seasons.

The location was perfect­, right at the foot of the Andes, in an unusual location in Argentina where major river systems flowed west into Chile, and temperate Pacific weather flowed up the valley to feed the rivers and temper the climate.

A drone photo of a large house or lodge in a green valley and bright sun.
(Isaias Miciu Nicolaevici photo)

At the end of the 2000/2001 guide season, the lodge owner stiffed them both. They didn’t get paid for more than 100 days of guiding. But during those first two seasons, they learned what made the Trevelin area so special, they made mental maps of the rivers, discovered lakes, and made plans to start their own outfitting business in Argentina.

They showed up in November 2001 with two rafts, all their fishing gear, and $10,000 in cash they had drawn with a cash advance from their personal credit cards. They were going for it. They bought two trucks, built custom frames to support inflated three-person rafts elevated above the truck frame, and became free-range fishing guides. Their guests stayed in cabins in the Trevelin and Esquel area, and they dined in local restaurants. Their motto was “to fish the best rivers, at the best times, with the best guides.”

In 2010, after successfully building and scaling the PRG brand, they bought the very same lodge building and property in Trevelin where they started, and the modern version of Patagonia River Guides (PRG) was born.

That lodge has been generously improved and expanded, and although they have a luxury “glamping” operation in the north called PRG Unplugged, and another in the south based out of the Estancia Tres Valles, the lodge at Trevelin is their home base, with 14 individual luxury rooms with en-suite bathrooms, a complete spa on the premises, and an outdoor wood-fired hot tub overlooking their 10-acre Contra Corriente vineyard. It’s a classic case of frontier entrepreneurial spirit, and an example of how a couple of Montana boys with nothing to their name can grow and build one of the largest outfitting businesses in South America (


While the majestic log building is likely the most comfortable fishing lodge in Argentina, it’s the location that makes PRG Trevelin so special. And by location I don’t mean a scenic property on a hillside overlooking the Rio Percy. By “location” I mean drawing a circle on a map with a 60-mile radius—basically everywhere you can drive to in about an hour. Everyone has a fishing range, whether it’s in the smallmouth bass rivers around your home, or from a skiff in the Florida Keys, but what’s special about this territory is how it stretches from the snow-capped peaks of Los Alerces National Park high in the Andes to hidden spring creeks on arid plains.

According to the Köppen-Geiger climate classification, there are eight different climate types near Trevelin ranging from arid cold desert to temperate warm summer. The geology ranges from the tectonic uplift that created the Andes, to volcanic calderas, and wide valleys carved by glaciers with rivers winding through remnant moraine. With this kind of mixed-up geology overlaid with complex climate types, it creates a fishing zone where you can fish in a completely different ecosystem each day for a week, and when it’s over, you still wouldn’t have scratched the surface.

When you fish the Bighorn for a week, or Pyramid Lake, or the Delaware, or the Louisiana bayous, each day is much like the previous one. The fishing environment doesn’t change. But there is no “typical” day at Trevelin because every day you fish in a completely different ecosystem with different flora, landscapes, terrain, and river bottoms. It’s like fishing roulette. The only thing that is constant is the fine wine and the pillow under your head.

It’s the variety here that gets my blood pumping, and although I’ve sampled only a fraction of what Patagonia River Guides has to offer, here are a few of the highlights.

Three fishermen in a blue raft float down a small river below craggy mountains.
(Isaias Miciu Nicolaevici photo)

Rio Grande

Technically, this is the Futaleufú, but everyone in the area calls the river flowing from Amutui Quimey Reservoir to the border with Chile the Rio Grande. It means literally, “big river.” The Rio Grande is the main artery in the Trevelin area, and its reservoir is fed by all the rivers coming from the wet, high-altitude Los Alerces National Park including the Rivadavia, Frey, and Menendez rivers. That’s a lot of water, and what flows from the hydroelectric turbines are 2,600 gigawatt hours of electricity and a giant tailwater of up to 10,000 cubic feet per second. This clear, cold, fertile water supports incredible weed growth and insect life with dense populations of caddis, mayflies, midges, and crustaceans like sow bugs and scuds. As in most tailwaters, midges make up a massive part of the invertebrate biomass, and they hatch nearly every daylight hour.

With these conditions, and a trout density that’s on par with familiar places like the Missouri, Bighorn, or the Green, there are some important differences between this tailwater and the ones you’re used to back home. Most important, practically no one is fishing it. You don’t see 50 boats dropping in at the boat ramp, partly because there are few if any government-provided boat launches. PRG drops their rafts in mostly through private property with access through farms, parks, or private riverside campgrounds. It’s a massive river, and difficult to fish without a boat.

A grayscale image of a fly-fishing guide gazing onto the water from a seat on a raft.
(Isaias Miciu Nicolaevici photo)

K.C. Walsh and I floated probably 6 or 8 miles with our guide Alex on a Saturday, and saw just two guys spin casting from shore, and one farmer ferrying supplies from his property on one side of the river to his sheep corrals on the other side. The land is fertile agricultural land just as you’d find in giant river valleys in North America. Tens of thousands of years of floods and silt  make good land for wheat, barley, and pasture land for cattle.

From the raft you can drift the placid waters and see trout feeding below you. You cast streamers into the tangle of willows lining the banks, tempting a steady parade of fat, 18- to 22-inch browns and a few rainbows. In the quiet seams along the bank, you’ll find trout quietly nodding at the surface, feasting on a mix of caddis, mayflies, and of course midges.

Even though it’s a tailwater, one thing the guides note about these Argentina rivers is that insects don’t tend to hatch in massive events as they do in North America. They hypothesize that over eons of evolution in North America, insects use dense hatches as a mechanism to ensure survival of the species, much in the way baitfish gather in giant schools to avoid predation.

A drone photo of a river spilling out of a lake in a forested landscape.
(Isaias Miciu Nicolaevici photo)

However, in these South American rivers, insects evolved in rivers without the threat of being eaten by trout or any other salmonids, and the aquatic insects emerge at a more leisurely pace through the day and through the seasons. It seems like there are constantly insects hatching, but they don’t all come at once. It gives the trout more opportunity for nonstop feeding, and it also makes them less selective.

A blanket hatch often makes even undisturbed fish very selective, but the fish on the Rio Grande are happy to snack on a variety of items, so Chubby Chernobyls, Purple Hazes, and Missing Link Caddis are good fly choices. Fly choice is much less important than just making a good cast, and making sure the fish sees it. And you don’t need to worry about bringing flies to PRG anyway: the guides have everything you need.


Just as the Jefferson, Madison, and Gallatin were named after two presidents and a cabinet member, the Rivadavia is named after Bernardino Rivadavia, the first president of Argentina. This river flows like a turquoise necklace from Lago Rivadavia, through a fjord-like trench between glaciated mountains, and into Lago Verde. This 4.2-mile slice of heaven is part of a chain of rivers and lakes that feed the Rio Grande tailwater downstream, and when guides in the morning tell you they want to fish “in the park” they most often mean this river in Los Alerces National Park.

Although the Rivadavia is fed by snowmelt and rainwater, the river level fluctuates very little, as its lake-fed source creates a stable spring creek environment flowing through a temperate rainforest with old-growth trees crowding the riverbank. On rivers that regularly flood, old trees are swept away and there are floodplains and wide gravel bars to wade and cast. Not here on the Rivadavia, where the river is tightly slotted between the forest and steep granite walls reaching for the sky. It’s like floating through the set of Jurassic Park, only there is no T-Rex chasing your Jeep, just hook-jawed brown trout chasing your streamer.

The bottom is a mix of mysterious submerged logjams and wide, white gravel and cobbled tailouts where you can clearly see trout feeding. It’s perfect habitat for trout to spawn, for insects to thrive—and also a great place for a big trout to run your line around a submerged log and break you off. That sort of thing happens on the Rivadavia every day.

By almost anyone’s definition, the Rivadavia is one of the world’s most beautiful trout rivers, but few people would see it if it weren’t for resident and migratory brown, rainbow, and brook trout that move back and forth between river and lake systems. The Rivadavia flows deep and silent, and it’s often much deeper than you imagine since you can see every stone on the bottom when the sun is high overhead. In this clear water, the fish have an uncanny habit of feeding in the shadows of woody structure, between a logjam and the bank, in a pocket between overhanging willows, or between two protruding logs. In our first hour on the river, we caught several heavy fish swinging streamers deep and slow near the outflow of the lake. As soon as the morning started to warm, we found a good trout rising to a sparse hatch of white/tan caddis. Each time we saw its porpoising head, it was directly under a broad, leafy branch reaching a rod length and 12 inches over the water.

Esteban anchored the boat off the bank, and due to the down-and-across nature of the presentation, K.C. undertook the tricky task of casting from the back of the raft, under the canopy of branches, landing the little dry fly just inches from the bank, and throwing multiple upstream reach mends to drift the fly downstream and under the lowest of the overhanding branches.

A fly angler and a fishing guide watch a drift from the banks of a small stream.
(Isaias Miciu Nicolaevici photo)

Making a cast like that one time is a feat. But each time the fly came down the lane, it seemed some other drifting insect distracted the steadily rising trout. K.C. duplicated the perfect presentation perhaps a dozen consecutive times until finally the 19-inch rainbow made a poor choice. It took the fly, and zippered the line upstream with the sound of tearing nylon. And so it went the rest of the day with choosy gold and red-striped trout rewarding us when we did everything right, and the mountainsides dripping their green reflections over the water.

Rio Corintos

At dinner one night, Rance described the Corintos as a “freestone spring creek,” which didn’t make sense to me at all until I actually waded the river. The Rio Corintos sits in a wide rolling valley with glaciated terraces on both sides. Glacial till can range from erratic boulders down to sand or fine powder, but the Corintos runs through a moraine of round, polished rocks the size of bowling balls at the heads of the pools and clean, pea-sized gravel in the shallow tailouts. If you can imagine a Madison River downsized to where you can wade calf-deep across every wide spot, a mini Madison where the trout see a passing fisherman perhaps every three or four weeks, as the beats are carefully rotated, this is it.

A grayscale image of two fly anglers watching a drift.
(Isaias Miciu Nicolaevici photo)

It’s a dry-fly paradise where my guide Mauri Techera wouldn’t consider even allowing a dropper nymph, as it would be against the spirit of this place. On the Corintos there’s no need to play dirty. You wade upstream, casting bushy dry flies into the sparkling riffles and deep green pools. In every run, you find trout willing to smack dry flies, and there’s no need to probe the depths as there is another pool, and more willing dry-fly fish, around each turn of the river. You won’t be able to fish it all before the day ends. Up- and downstream there are dozens of other beats. Some sections are easier than others to access by truck, others require a fair amount of hiking. If you are willing to hoof it a mile or two, you may volunteer yourself for a beat that hasn’t been fished at all that season. I did that, and my first three casts of the day produced three chunky 16-inch brown trout in a row.

The irregular, clean bottom has the look of a riverbed washed by annual floods from rain and snow. But during the summer, most of the flow comes from cold springs. On both sides along almost the entire course of the river there are seeping bogs, trickling rivulets, weeping cliffsides, and even spring-fed waterfalls that constantly cool and feed the river through its course. As Rathie said, it’s a freestone spring creek.

A fishing guide netting a large brown trout for a fly angler on a clear-water stream.
(Isaias Miciu Nicolaevici photo)


The Gauljaina sneaks up on you because it’s a river without a valley. You arrive to a pasture on high arid steppe with nothing but grass and blue sky for as far as you can see, and as you bump through the fields in a white Toyota Hilux, a string of willows appears in the distance, pointing like a finger toward the distant mountains. You could be in a cow pasture just about anywhere. You don’t see the water until you’re right on top of it because there is no eroded canyon or any other geomorphic signs to tell you a river should be here . . . it just is.

The Rio Gauljaina seeps from the ground in a boggy wetland, and is joined by two other spring creeks—the Tecka and the Pescado—before it snakes through an otherwise dry 30,000-acre estancia that is a checkerboard of pastures for sheep and cattle, and lots of locked gates. If it wasn’t for this upwelling of groundwater, the livestock could not survive in this arid landscape.

It doesn’t matter what country you’re in, it’s good to know a rancher with this amount of land and cattle, as they understandably don’t allow just anyone to traipse across their fields. As I sat on the tailgate with K.C. Walsh, we pulled on our waders and Rathie explained that if you started fishing your way upstream from where we were parked, it would take 60 or 80 days of fishing to reach the edge of the estancia. No PRG guest sees the same spot twice, and in 20 years of fishing it, Rathie still hasn’t seen it all.

The low-gradient Gauljaina winds slowly back and forth through the pastureland, creating a river where there may be 5 miles of river inside of one square mile of fenced land.

A collage of Patagonia trout-fishing and luxury lodging images.
(Isaias Miciu Nicolaevici photo)

It’s a small stream by any measure. Willows in places constrict the flow to a deeper slot where you likely couldn’t stand, but it’s mostly knee-deep to waist-deep with green beds of elodea, hydrilla, and waving strands of coontail. The aquatic plants are crawling with scuds, tiny mayflies, and free-ranging caddis, and I imagine those aquatic food sources make up the bulk of the trout diet here. But the trout must be really sick of eating those tiny morsels because if you drop a Dave’s Hopper in front of them, they go absolutely bananas.

On my first morning on the Gauljaina we found a 19-inch rainbow feeding confidently just inches from a grassy bank on what looked like size 18 Blue-winged Olives. He hovered just under the surface, and I could plainly see the red stripe and the freckles on his snout as he took each passing mayfly. I haughtily told my guide Juan that I was already tired of the hopper gluttony, and I wanted to match the hatch. So I tied on a perfect little Parachute I tied myself, with a synthetic wing post and split Microfibetts tails. I had the perfect fly and the perfect fish, but I overcompensated for that gusting wind blowing across the plains, and my fly landed just 2 feet to the right of my target. The rainbow sitting just under the surface didn’t see the fly at all, but a 21-inch brown that was sitting deeper in the channel charged forward and took the fly like a dog catching a Frisbee. Plan foiled. I went back to the hopper.

Is the fishing here easy? Hell no, but it is incredibly rewarding if you can cast. There is no shelter from the wind, and in the fishiest spots, the river is only 3 or 4  feet across. The guides observe many, many casts that don’t even hit the river, let alone the target. The trout love to eat hoppers, but they often sit at the heads of pools crowded by overhanging willows, and you have to defeat the wind, thread the needle under or around the willows, and land the fly in just the right spot without spooking the fish. Do that consistently, and your hands will be full of fat, colorful spring creek trout up to about 23 or 24 inches. It’s the ultimate “big fish in small water” experience.

Lago Menendez

PRG has private access to numerous lakes in the region, including Lago Martillo, the Fruit Lakes, and many others, but perhaps the crown jewel in terms of breathtaking scope and beauty is Lago Menendez in Alerces National Park. Anyone can go there, it’s a national park preserved for the enjoyment of all, but access is only by boat or by hiking. It’s a true wilderness alpine lake with no road access.

A decade or more ago, the invasive algae Didymosphenia geminata appeared in Chile and began spreading up the Futaleufú into Argentina, presumably transported on rafts, kayaks, or fishing boots. To preserve the pristine Lago Menendez, the government prohibited any new boats from coming upriver into the lake. Esteban Oszust, who grew up in a home inside the national park, and whose father worked for the national park, already had one of four boats moored at the small pier at Puerto Chucao. It’s the only fishing boat on the lake. The other boats are a park service boat and two larger tourist boats that run daily trips to see the Torrecillas glacier and the massive alerce trees (Fitzroya cupressoides), at the far end of the lake.

Oszust is the head guide at PRG Trevelin and takes just a handful of guests per season to the Y-shaped lake that covers more than 20 square miles. The blue-back rainbows and caramel browns in Menendez gather in small shoreline coves where the wind collects food. They are easy to spot and they ravenously attack large surface flies. We used a fly called the Gypsy King Rance Rathie developed 15+ years ago to imitate cantaria beetles (Chiasognathus grantii), but the Gypsy King is not a bad salmonfly, cicada, or dragonfly either. Trout in Lago Menendez could spot this fly from 10 feet away, and when they did, they didn’t slowly meander toward it.

A fishing guide holds up a large brown trout while his client looks on and smiles.
(Isaias Miciu Nicolaevici photo)

This lake is somewhat of a sacred placed for Oszust, the Argentina nation, and should be for you as well. You can catch as many 16- to 20-inch fish as you wish—all sight fishing with dry flies—but take time to breathe deeply and smell the forest, wonder at the massive blue hanging glaciers feeding the lake with a hundred ribbons of waterfalls, and walk quietly among the alerces trees. The forest is a Unesco World Heritage site where you can see massive, ancient specimens from the cypress family. These are among the oldest living organisms on the planet. The largest in the park is 187 feet (57 m) tall, 7.2 feet (2.2 m) in diameter, and is estimated to be 2,600 years old. Tread lightly among the giants, listen for the crack of breaking ice as it falls from the glacier, catch a few fish and let the rest pass unmolested, and be grateful that there are still places like this left in the world.

Recommended Gear

A gear locker showing many pairs of waders and boots.
(Isaias Miciu Nicolaevici photo)

PRG makes international travel easy by providing all the gear for their guests. They have hundreds of Simms waders and boots of all sizes, more than 60 Winston Air2 rods with Abel reels and Airflo Power Taper lines, and all terminal tackle including flies. It’s possible to travel there with just a carry-on bag and have everything provided for you. If you wish to bring your own gear, here’s my packing list.

Book your Destination

To inquire about a trip to Patagonia River Guides at Trevelin, Argentina, contact Pat Pendergast at The Fly Shop in Redding, California (800-669-3474);

Ross Purnell is the editor and publisher of Fly Fisherman.

A wader-clad fly angler kneeling and holding a large brown trout, smiling at the camera.
Get your copy of Destinations 2023 here. (Zach Heath photo)

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