Gertie, The King Octopus: What’s Lurking in the Tacoma Narrows

Deep down in the murky waters of the Tacoma Narrows, a real-life monster lurks. Its tentacles ensnare prey, and its radula scrapes meat from bone. The Tacoma Narrows Octopus sleeps in a bridge’s wreckage … and waits for you. Get the monstrous profile after the jump.

A History of King Octopus Sightings

Chilling Encounters with Super Cephalopods

Between 1900 – 1929, the press couldn’t get enough of devilfish and octopus encounters. Let’s just say, there may have been some sensationalized retellings, like classic fishing stories. Even the most benign encounter made the news … unless death was involved … then it landed on the front page.

In 1919, “The Trail of the Octopus,” became the most talked serial in Tacoma. It was a thrilling action/adventure/monster mashup. People lapped up every little octopus (or squid) encounter they could get. And it helped sell papers to boot.

By the 1930s, the octopus fervor settled down. Once people realized cephalopods were gentle creatures, well, they became disinterested.

A Monster That Really Exists

So, about that gigantic octopus … turns out it was real after all. Maybe not quite as big as fishermen will tell you.

The giant Pacific octopus (GPO) was “discovered” in 1910. I put discovered in quotes because these buggers has always been in the north Pacific Ocean. It wasn’t until 1910 that German scientist, Gerhard Vülker, described it in detail.

I’d be remiss if I didn’t list its attributes (for an average specimen) here:

• Grows 12′-14′ wide (tip-to-tip)
• Weighs 40lbs-100lbs
• Changes colors to match its surroundings (red by default)
• Has blue blood (it’s copper-based, not oxygen-based like mammals)
• Contains 2.5″ side suckers
• Lives 3-5 years
• Dies after mating

A female can lay up to 400,000 eggs, with most being eaten by predators. She will wait 6 months for her brood to hatch, never leaving them even to feed, and will starve to death. As for males, they usually die shortly after mating as well.

As for the largest specimen, I found a newspaper article from the 1910s listing that as 23-feet across and weighing 165 pounds. It was captured in San Francisco Bay. Now that’s a real big octopus!

How The Legend Developed

From what I can tell, the King Octopus legend started after Gallopin’ Gertie collapsed into the Narrows. Construction divers started to bump into giant Pacific octopuses. They’d get freaked out by the long, slithering tentacles in the murky depths. Fear and imagination can ramp those fish tales.

But it wasn’t until Douglass Brown told the tale of the massive tentacle rising from the depths of Puget Sound in the late 1950s that the legend really took off. It probably got boosted by all those octopus wrestling games from the period, too.

By the 1970s, most of the tales had died down, and you don’t really hear much about the King Octopus nowadays.

I still think we should think about that super-sized octopus though … just for fun.

The King Octopus’ Den

Two hundred feet below the surface, Gertie, the nickname for the King Octopus, lurks in the wreckage of the 1940 bridge collapse. All that roadway, concrete and metal made a reef. Octopuses and other sea life swarmed in and set up shop.

Gertie’s den (red star above) formed from a section of the bridge that looks somewhat cavernous. It would be able to hold the monstrous cephalopod. Speaking of which, Gertie is said to be a 600-lbs. deep red monster that has 30-foot long tentacles. She’s thought to hunt whales, dolphins, small octopus … and an occasional diver. Pulling kayaks under the water is another pastime of hers.

How An Octopus Becomes Gigantic

The giant Pacific octopus is the biggest octopus on the planet, but even it has growth limits. The question is: How would an already monster-size octopus grow to King Octopus size?

First things first, its habitat and food supply would big the two biggest factors with a dose of mutation.

The giant Pacific octopus is a fast grower: It can reach 90-lbs. and 12-feet wide in a year. To do that, they need to eat 2%-4% (that’s about 2 crabs) of their body weight a day. That’s a lot of clams, oysters, crabs, fish, scallops, and whatever dead critter is in the water.

Now, the Narrows is a nutrient- and oxygen-rich environment, so you could say octopus would get a lot of vitamins and minerals to help it grow.

Still, reaching 600-lbs. and 30-feet across? That would require mutation. (Note: No octopus specimen has been documented to be this size, but the colossal squid can be even bigger.)

The Most Plausible Mutations

Endocrine Mutation: Suppressed Senescence Gene

• Real GPOs die shortly after mating because of optic gland hormone cascades (similar to a pituitary gland in mammals).
• A mutation that disables or delays optic gland degeneration would let an octopus keep growing indefinitely.
• Result: Lifespan could stretch to decades, allowing a truly colossal size.
• Real-world analog: experiments at the University of Chicago (2019) found that removing optic glands in female GPOs stopped senescence and prolonged life, so a King Octopus could plausibly arise from a natural mutation or chemical pollutant that mimics that effect.

Genetic Drift via Isolation & Environmental Contaminants

• The Narrows region was heavily industrialized through the 20th century: pollutants such as PCBs, heavy metals, and hydrocarbons can cause mutations in marine life.
• Combined with the isolation of individuals living deep within the Galloping Gertie wreckage, this could produce founder-effect divergence; a tiny population evolving separately over many generations.
• Result: a local subspecies, Enteroctopus dofleini gertiensis, the “King Octopus of the Narrows.”

Regenerative Overexpression

• Octopuses can regenerate arms.
• A mutation that causes systemic overexpression of regenerative tissue could make cells replicate far beyond normal repair, which is similar to uncontrolled gigantism.
• Secondary side effect: accelerated neural growth and larger brain size, giving the “King” higher intelligence and complex behavior, possibly even recognizing human divers as threats.

What To Do If A Giant Octopus Comes For You

First, relax. Octopuses don’t go looking for trouble. They’re reclusive, shy, and not fond of human flesh. They may reach out and wrap a slimy tentacle around your ankle. That’s because they’re curious about this crazy land dweller swimming in their territory. Once they figure out you’re not food, they’ll let you go and swim away.

And then you’ll have a fishing tale to tell your friends when you have calamari for dinner.

Sources

Atlas Obscura. “The Giant Pacific Octopus Monster of Tacoma.” Atlas Obscura, 23 Feb. 2017, https://www.atlasobscura.com/articles/giant-pacific-octopus-monster-tacoma.

Bay Nature. “When Octopuses Thrived in San Francisco Bay.” Bay Nature, 22 Feb. 2022, https://baynature.org/article/octopuses-thrived-san-francisco-bay/.

Grit City Magazine. “Kraken: The Case Behind One of Tacoma’s Most Popular Local Legends.” Grit City Magazine, 14 Mar. 2018, https://gritcitymag.com/2018/03/kraken-the-case-behind-one-of-tacomas-most-popular-local-legends/.

Harbor History Museum. “The Mystery of the Misunderstood Cephalopod.” Harbor History Museum Blog, 2020, https://www.harbormysterymuseum.org/post/the-mystery-of-the-misunderstood-cephalopod.

KUOW. “There Really Is a Giant Octopus under the Tacoma Narrows Bridge.” KUOW Public Radio, 27 Oct. 2017, https://www.kuow.org/stories/there-really-giant-octopus-under-tacoma-narrows-bridge/.

National Geographic. “Giant Pacific Octopus.” National Geographic Animals, 2023, https://www.nationalgeographic.com/animals/invertebrates/facts/giant-pacific-octopus.

Ocean Portal, Smithsonian Institution. “Revealing the Largest Octopus.” Ocean.si.edu, Smithsonian, 2021, https://ocean.si.edu/ocean-life/invertebrates/revealing-largest-octopus.

Seattle Aquarium. “Giant Pacific Octopus.” Seattle Aquarium, 2024, https://www.seattleaquarium.org/animal/giant-pacific-octopus.

Tacoma, City of. National Register Nomination: Tacoma Narrows Bridge Ruins. City of Tacoma Historic Preservation Office, 2006, https://cms.cityoftacoma.org/planning/historic-preservation/NominationDocs/NarrowsRuins.pdf.

Wikipedia. “Cephalopod Size.” Wikipedia, 2024, https://en.wikipedia.org/wiki/Cephalopod_size.

Further Reading & Viewing

Books & Research

• Cosgrove, James A., and Neil McDaniel. Giant Pacific Octopus: The World’s Largest Octopus. Harbour Publishing, 2009.
• Hochberg, Frederick G., et al. Cephalopods: A World Guide. ConchBooks, 2006.
• Norman, Mark. Cephalopods: A World Guide to Squid, Cuttlefish, Octopuses, and Allies. Ivy Press, 2018.
• Wood, James B., and Roland C. Anderson. Octopus: The Ocean’s Intelligent Invertebrate. Timber Press, 2010.

Documentaries & Multimedia

• “Octopus: Making Contact.” PBS Nature, 2019.
• “Secrets of the Giant Pacific Octopus.” Smithsonian Channel, 2021.
• “The Legend of the Giant Octopus.” KUOW Radio Feature, 2017.

Historical & Folklore Context

• “World Octopus Wrestling Championships Once Attracted Thousands to Tacoma.” KNKX Public Radio, 20 May 2017.
• “The Octopus under the Narrows Bridge Named One of Tacoma’s 11 Wonders.” Patch, 2020.
• “Tacoma’s Kraken: From Galloping Gertie to Giant Legends.” Grit City Magazine, 2018.

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Have you encountered a sea monster? If so, let me know in the comments. Thanks for reading Puget Sound Monster Club. Much appreciated and take care!