The king salmon is the newest and by far the biggest fish an angler can chase in Argentina. A true Pacific salmon that colonised Patagonia’s southern rivers within living memory, the chinook now runs up the Río Santa Cruz and its neighbours at sizes that dwarf every trout in the country — fish of 30, 50, even 90 pounds. It is a young, raw and still little-known fishery, and one of the most extraordinary big-fish stories in the fly fishing world.
Chinook salmon in Argentina — the facts
- Species: Chinook salmon, Oncorhynchus tshawytscha — the largest of the Pacific salmon.
- Also called: king salmon; salmón chinook / salmón rey (Spanish).
- Status: introduced to the Pacific coast decades ago; now a self-sustaining, sea-run population in southern Argentina.
- Average size: 30–45 lb, with fish of 60–70 lb regular and specimens near 90 lb landed.
- Where: Río Santa Cruz, Río Gallegos, Río Grande and Río Corcovado, among others.
- Season: roughly December to April, as the run builds through late summer and autumn.
- Top tactics: heavy sink-tips, two-handed rods and big streamers.
Chinook or king salmon — and how it got to Argentina
First, the names: chinook and king salmon are the same fish — Oncorhynchus tshawytscha, the largest of the Pacific salmon species. “King” is the common North American name; “chinook” is the formal one. What makes the Argentine fishery remarkable is that these salmon are not native to the Atlantic side of South America at all. They descend from Pacific salmon-farming experiments in southern Chile in the 1980s: fish escaped and strayed, the first spawning chinook were confirmed in Patagonian rivers around 1996, and DNA later tied them back to those Chilean sea farms. From those accidental beginnings a genuine, self-sustaining sea-run population has established itself — salmon that now hatch in Argentine rivers, migrate to the South Atlantic to feed, and return years later to spawn. It is one of the only places on earth where a wild chinook run has taken hold outside its native range.
Where to catch king salmon in Argentina
The chinook fishery is concentrated in the far south, in Santa Cruz and Tierra del Fuego:
- Río Santa Cruz: the largest and most famous of the runs — big water for big fish.
- Río Gallegos: better known for sea trout, but it also receives a chinook run.
- Río Grande and Río Irigoyen (Tierra del Fuego): periodic runs of kings alongside the famous sea-run brown trout.
- Río Corcovado (Chubut): and other Pacific- and Atlantic-slope rivers see chinook as the population expands.
Because it is a young fishery, much of it is still remote and lightly fished — part of its appeal for the adventurous angler.
How big do king salmon get?
This is a fishery built on size. In Patagonia, chinook of 30–45 pounds are common, fish of 60–70 pounds are caught regularly, and the largest landed have approached 90 pounds, with at least one lodge record of 91. For context, the world all-tackle record chinook — 97 pounds 4 ounces, caught on Alaska’s Kenai River in 1985 — has stood for over forty years, which puts the scale of Patagonia’s biggest fish into perspective. These are, without exaggeration, the largest fish an Argentine fly angler can hook.
Do king salmon die after spawning?
Yes. Like all Pacific salmon, the chinook is semelparous — it spawns once and then dies, its life ending on the gravel where the next generation begins. This is a key difference from Argentina’s Atlantic salmon and its sea-run brown trout, which can survive and spawn again. It also shapes the fishing: kings are targeted as they run in fresh and strong from the sea, before spawning takes its toll, when they are at their heaviest and most powerful.
When to go
The king salmon run builds through the austral summer and autumn, with fishing generally from around December into April and the greatest numbers of fish in the rivers from late December onward. As with all of Patagonia’s premier fisheries, remote access and limited operations mean planning ahead pays off. See the best time to fly fish Argentina for the wider seasonal picture.
How king salmon are fished
Landing a fish that can weigh more than the angler’s tackle bag calls for heavy gear and a particular approach:
- Two-handed rods: spey and switch rods in 8- to 10-weight give the reach and backbone to move big fish in big water.
- Heavy sink-tips: getting the fly down deep and slow, where the kings hold, is the whole game.
- The swing and the strip: swinging large flies through holding water, or stripping them past resting fish, to trigger an aggressive grab.
- Strong tackle throughout: heavy leaders, strong hooks and a reel with a serious drag — a fresh king will test everything.
Flies for Patagonian king salmon
Like all salmon in fresh water, chinook are not feeding, so flies are chosen to provoke a territorial or aggressive response through size, colour and movement:
- Intruders and big articulated streamers: the go-to for kings — large, mobile profiles that push water.
- Tube flies: heavy tubes that ride on sink-tips and get down to holding fish.
- Bold colours: chartreuse, pink, orange, black and combinations of them, plus flash and UV materials for coloured or deep water.
Guides and lodges carry the patterns that work on their particular river, and will match colour and weight to the day’s flow and clarity.
Handling and conservation
Chinook are a powerful, hard-won fish and, as a naturalised population, an important part of the modern Patagonian fishery. Handle them with the respect their size demands: strong tackle to land them quickly, minimal air time, and careful release of fish that are not spawning out. Playing a big king to exhaustion in warm water is hard on the fish, so land them efficiently and let them go strong.
Plan your Argentina king salmon trip
Chasing the largest fish in Patagonia on a fly rod is a raw, remote adventure — and a young fishery still finding its fame. Tell us your dates, budget and experience, and we will match you with the outfitters running these southern rivers.
Frequently asked questions about Chinook (King) Salmon
Are chinook and king salmon the same fish?
Yes. Chinook salmon (Oncorhynchus tshawytscha) and king salmon are two names for the same species — the largest of the Pacific salmon.
How did Pacific salmon get to Argentina?
They descend from salmon-farming experiments in southern Chile in the 1980s. Escaped and straying fish established a self-sustaining sea-run population in Patagonian rivers, with the first spawning chinook confirmed around 1996 and DNA later tying them to the Chilean farms.
How big do king salmon get in Patagonia?
Chinook of 30–45 pounds are common, fish of 60–70 pounds are caught regularly, and the largest landed have approached 90 pounds — the largest fish available to Argentine fly anglers.
Do king salmon die after spawning?
Yes. Like all Pacific salmon, the chinook spawns once and then dies, unlike Atlantic salmon and sea-run brown trout, which can spawn more than once.
Where is the best king salmon fishing in Argentina?
The Río Santa Cruz holds the largest and most famous run, with chinook also caught in the Río Gallegos, Río Grande, Río Irigoyen and Río Corcovado in the far south of the country.
What is the world record chinook salmon?
The IGFA all-tackle world record is a 97-pound-4-ounce chinook caught on Alaska’s Kenai River in 1985 — a record that has stood for over forty years. Patagonia’s biggest kings, near 90 pounds, are not far off.
When is king salmon season in Patagonia?
The run builds through the austral summer and autumn, with fishing generally from around December into April and the greatest numbers of fish in the rivers from late December onward.
How are king salmon fished?
With heavy gear: two-handed spey and switch rods in 8- to 10-weight, deep sink-tips to reach holding fish, and large flies swung or stripped to trigger an aggressive grab. Strong leaders and reels with a serious drag are essential.
What flies work for Patagonian king salmon?
Intruders and big articulated streamers that push water, heavy tube flies that ride on sink-tips, and bold colours — chartreuse, pink, orange and black — with flash and UV for coloured or deep water.
Is the Argentine king salmon fishery wild?
Yes. Although the fish originally came from Chilean fish farms, they now hatch in Argentine rivers, migrate to the South Atlantic and return to spawn — a genuine, self-sustaining wild run, one of the only established chinook runs outside the species’ native range.