What Is a Pink Salmon? The Odd-Year Invasion of Puget Sound

What Is a Pink Salmon? The Odd-Year Invasion of Puget Sound

Every two years, in the churning tides of Puget Sound, a silver wave rises. From the open Pacific, pink salmon—Oncorhynchus gorbuscha—return in the millions. They surge through Admiralty Inlet and crowd into places like Humpy Hollow, near Mukilteo, where they pause to feed before their final journey upstream.

This is not a subtle event. It is a spectacle. Rods bend, boats bob, and beaches buzz with anglers chasing the pulse of a fish that lives fast, runs thick, and dies young.

But what exactly is a pink salmon?

The Life of a Humpy

Pink salmon are the smallest of the Pacific salmon—usually just 3–6 pounds—but don’t let their size fool you. These fish are scrappy, stubborn, and built to get the job done in a hurry.

Their entire lifecycle is only two years long. Born in freshwater streams, pink fry waste no time—they head downstream almost immediately after hatching. Within days, they reach the saltwater of Puget Sound and begin feeding, growing, and schooling up.

From there, they head out into the open ocean, traveling across the North Pacific as far as the Gulf of Alaska, building strength and size. It’s a quick sprint through life—eighteen months at sea—before their internal compass starts calling them home.

That means every fish you see this year was born during the last run. And every fish this year will give rise to the next. It’s a perfectly timed, biological relay race.

Why Only Odd Years?

Here’s one of the great quirks of pink salmon: in Puget Sound, they only return in odd-numbered years—2025, 2027, and so on. But this isn’t true everywhere.

In Alaska, British Columbia, and parts of Russia, pink salmon return every year. That’s because those regions maintain both odd- and even-year populations. Each generation is genetically distinct, with no crossover—almost like two separate species.

But in Puget Sound, we only get the odd-year team.

From what I’ve read—and what a few old-timers around here will tell you—it might’ve been some kind of major disruption that wiped out the even-year fish. A big flood, disease outbreak, habitat loss, or even something weird like volcanic ash or underwater landslides. Since pinks only spawn once, exactly two years after they’re born, losing a whole generation means losing an entire cycle.

Could the even-year run have been wiped out while the odd-year fish were out at sea? It’s possible. And once they're gone, unless some fish from another system wander in (a rare event), that cycle doesn't come back.

Scientists believe it was likely a mix of reproductive isolation, poor survival, and possibly a catastrophic event that pushed the even-year group past the tipping point. Whatever it was—it left Puget Sound with one of the strangest pink salmon patterns in the world.

Why They Pool Up in Humpy Hollow

As pinks return from sea, they navigate through the Strait of Juan de Fuca and into Admiralty Inlet. Then, something special happens.

Just off Mukilteo, at a bend in the Sound known as Possession Point, the fish turn. It’s not just a directional shift—it’s a pause. A staging ground.

Humpy Hollow, as anglers call it, becomes the pregame locker room. Here, pink salmon stack up in huge schools to feed, rest, and prepare for their final push into freshwater. It’s like a pit stop for salmon: last chance to refuel before burning every last calorie in the upstream battle ahead.

The water here swirls with current, baitfish, and cold upwellings—making it the perfect buffet. And for anglers? It’s a concentrated, target-rich environment. That’s why boats, kayaks, and shore casters all flock to this stretch when the run is on.

The Look and the Hump

In saltwater, pinks are sleek and silver. But once they hit freshwater, the transformation begins.

Males morph into hunched river gladiators. Their backs rise, jaws hook, and colors darken into greenish and pinkish hues—earning them the nickname “humpies.” Females don’t hump up, but they’re just as determined, carving out gravel nests (redds) for the next generation.

It’s quick, it’s brutal, and it’s all over in weeks.

Loved, Underrated, and Always Fun

They’re not trophy fish. They don’t fetch big prices. But to many anglers, pinks are the most fun you can have with a rod in your hand.

Why?

  • They’re aggressive biters

  • They fight hard for their size

  • They’re accessible to everyone—shore, boat, pier, kayak

  • And when the run is on, the action is nonstop

And yes—they’re delicious fresh (especially smoked), even if they don’t freeze as well as other salmon.

Why Humpy Hollow Exists

This page—Humpy Hollow—was born out of respect for this incredible fish and the fishery they fuel. Our namesake stretch of water is where pinks stack up on their journey home. It’s a spot, a tradition, and a vibe.

Whether you’re brand new to pink salmon or a seasoned humpy hunter, welcome.

Image by Totti, via Wikimedia Commons, licensed under CC BY-SA 4.0.

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