Colossal Claude: The Columbia Bar Sea Monster

Colossal Claude, the Columbia Bar sea monster, first made headlines in 1934. For the rest of the decade, it thrilled and spooked fishermen near Astoria, where the Columbia River meets the Pacific. By 1960, the sightings had trailed off. But Claude still left a monstrous mark. Get the scoop after the jump.

How Witnesses Describe Colossal Claude

Witness reports have varied, but there are a couple of points they agree on:

Claude has a long, thin neck (about 8-feet long) and a thick, round body. It’s also about 40-50 feet in length. However, the witnesses stated the body was underwater, so they’re making an assumption about how long Claude is. Objects underwater tend to look larger than they actually are. Claude could be smaller than reported (possibly in the 25–40 ft range), especially if witnesses saw only partial body + wake in heavy chop.

After that, the reports vary. Especially with its head and skin. Some reports say Claude has a horse- or camel-shaped head. Other reports described the head as reptilian. As for the skin, one of the more credible eyewitness accounts describes … fur.

Habitat & Range

Claude isn’t really a river monster: It’s very much a sea monster. You see, it hunts and lives where the Columbia River meets the Pacific Ocean. This is a brackish water area, where salty sea water meets fresh water. Specifically, it hunts in the dangerous waves and shifting sand of the Columbia Bar.

If we examine the sightings, witnesses report Claude at the Columbia River estuary and along the Oregon coast. Not farther east in the river. So, it’s definitely not a river monster.

These clues indicate Claude prefers colder water and one that supports plentiful fish stock. That makes perfect sense since a big sea monster needs a lot of food.

Here’s what’s likely on Claude’s daily menu:

• Schooling baitfish (like herring)
• Salmon (likely steelhead)
• Pacific lamprey
• Bottom fish + flatfish (like flounder)
• Squid

As for sea mammals like seals and sea lions, it might eat a sick seal or carrion. But a healthy sea lion is going to put up a fight that Claude doesn’t want to get into.

Cryptid Behavior

Observed Behavior

For a sea monster (or serpent), Claude acts more like a sea mammal. It appears to be comfortable with humans because it comes close to shore and fishing trawlers. The creature also has no qualms about snatching fish off lines close to the surface. And the other thing: Claude observes humans and doesn’t display fear.

Then again, a sea monster of this size isn’t worried about humans eating it, unless it’s been attacked by people. That hasn’t happened, so it hasn’t learned to avoid us pesky primates.

Inferred Biology (Speculative)

Over the years, no one has found a nest or lair for Claude, so this makes me think it swims out of deeper ocean waters to sleep. Additionally, there are no reports of strange skeletons or carcasses found.

Hunting Tactics

Take these as speculative since we’ve only observed Claude feeding from fishing lines. It’s reasonable to assume that Claude would use these methods:

• Likely to burst upwards into a school of bait fish
• Pluck fish from lines or rip nets open to feast
• Weave through jetties to capture prey hiding among posts
• Feed at night to disguise its large frame in murky waters

Key Sightings Timeline

Witnesses made numerous reports of a sea monster in the Columbia River estuary during the 1930s, but it all seemed to end by 1960. There was a possible encounter in 1989, when a fishing trawler had its nets grabbed, and pulled so hard, its bow dipped in the water. When the crew retrieved the net, it had a large hole in it. But no one actually saw what creature may have grabbed it.

For all we know, Claude and its species have migrated away from the Pacific Northwest.

How To Hunt For Colossal Claude

Let’s be clear: Hunting means documenting and collecting physical evidence of a monster, ok? No harming of cryptids allowed. Now, back to the post …

For Claude, I think it’s best to use observation to “hunt” for it. You can set up your camp on either side of the Columbia River (Washington to the north, Oregon to the south) and watch. Documenting whatever anomalies you find.

There’s also the option to rent a fishing boat. It likely has a sonar to find underwater anomalies, but that churning, choppy water would be tough to work in. Not sure if it’s worth the cost.

Here’s the plan:

Safe Observation Points

• High overlooks near the river mouth and jetties (stay behind barriers, respect closures)
• Any spot where you can watch shipping lanes and breaks from elevation

What To Document

• Time, tide, weather, swell height (estimate), visibility
• Exact location and direction you were facing
• How long you watched the thing
• What it did in three verbs (rose, arched, sank)

Suggested Gear

• Binoculars
• Phone with compass app (or actual compass)
• Camera with a real zoom if you have it
• Notebook, because your brain lies to you later
• Audio recorder (because I find it more effective to say what I’m seeing)

A Skeptic’s Perspective: What Claude Might Be

If we scrutinize the eyewitness accounts, which is all we have to go on, there’s one simple explanation for Claude, and that’s …

Sea lions.

If we look at the furry sea monster report, its curious nature about humans, and its opportunistic hunting of fishing lines … it all points to sea mammal behavior. And the biggest sea mammal in the area is a sea lion.

It would only take 4 or 5 sea lions swimming in a line to reach the length of Claude. In all that chaotic and churning water, a group of sea lions could easily be mistaken for a serpent.

From a naturalistic perspective, my money is on sea lions.

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Common Confusion: Colossal Claude Vs. Marvin The Monster

Many folks seem to confuse Claude with another sea serpent reported in 1963. Marvin The Monster is a 15-foot long serpent with barnacled ridges that moves in a corkscrew motion. It was sighted with underwater cameras at a Shell Oil drill site near the Oregon coast.

No one really knows what this monster is, and no one has seen it since that one sighting. Anyway, the folklore kicked in and people started combining Claude with the Marvin critter. But, really, they’re two different cryptids.

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Further Reading

Oregon Encyclopedia, “Sea Serpent Lore” (best single overview of Claude reports and the Marvin add-on). Oregon Encyclopedia

U.S. Light House Society, Lightship LV-088 station assignments (useful for the lightship context around the Columbia River mouth). USLHS Digital Archive

Columbia River Maritime Museum, Lightship Columbia info (for local context and the physical “here’s the ship” angle). Columbia River Maritime Museum

Bibliography

La Follette, Cameron. “Sea Serpent Lore.” The Oregon Encyclopedia, Oregon Historical Society and Portland State University, 15 Apr. 2022. Accessed 8 Jan. 2026. Oregon Encyclopedia

Columbia River Maritime Museum. “Lightship Columbia.” Columbia River Maritime Museum, n.d. Accessed 8 Jan. 2026. crmm.org

Delzado, James P. “Lightship WAL-604 ‘Columbia’ / Columbia WLV-604.” National Register of Historic Places Registration Form, National Park Service, 30 June 1989. Accessed 8 Jan. 2026. NPGallery

Harris, Michelle. “The Pacific Northwest Is Crawling With Cryptids, and Not Just Bigfoot. Here’s How to Dress Like One of Oregon’s Other Monsters for Halloween.” Willamette Week, 29 Oct. 2019. Accessed 8 Jan. 2026. Willamette Week

National Weather Service Portland, OR. “Local Bar Observations.” National Weather Service (NOAA), n.d. Accessed 8 Jan. 2026. National Weather Service

United States Coast Guard. “Columbia River Bar Crossing Handout.” U.S. Coast Guard Pacific Area (Northwest District), n.d. Accessed 8 Jan. 2026. Pacific Area USCG

United States Coast Guard Historian’s Office. U.S. Coast Guard Lightships & Those of the U.S. Lighthouse Service: U.S. Lightship Station Assignments. U.S. Coast Guard, 28 Sept. 2020. Accessed 8 Jan. 2026. U.S. Department of Defense

United States Lighthouse Society. “Columbia River (Lightship Station).” USLHS Digital Archive, n.d. Accessed 8 Jan. 2026. archives.uslhs.org

“California Sea Lion: Conservation & Management.” NOAA Fisheries, National Oceanic and Atmospheric Administration, accessed 8 Jan. 2026. NOAA Fisheries

“Gloucester Sea-Serpent Mystery: Solved after Two Centuries.” Skeptical Inquirer, 2019. Accessed 8 Jan. 2026. skepticalinquirer.org

Kowalczyk, N. D., et al. “Selective Foraging within Estuarine Plume Fronts by an Inshore Resident Seabird.” Frontiers in Marine Science, 2015. Accessed 8 Jan. 2026. Frontiers

Phillips, E. M. Characterizing Juvenile Salmon Predation Risk during Early Marine Residency near the Mouth of the Columbia River. NOAA, 2021. Accessed 8 Jan. 2026. NOAA Institutional Repository

Ross, Helen E. “Water, Fog and the Size–Distance Invariance Hypothesis.” British Journal of Psychology, vol. 58, 1967. Accessed 8 Jan. 2026. bpspsychub.onlinelibrary.wiley.com

“Sea Serpent Lore.” The Oregon Encyclopedia, Oregon Historical Society. Accessed 8 Jan. 2026. Oregon Encyclopedia

“What Causes Ocean Waves?” NOAA Ocean Exploration, National Oceanic and Atmospheric Administration, updated 14 Sept. 2022. Accessed 8 Jan. 2026. NOAA Ocean Exploration

“Your Visual Guide to Sea Lion and Seal Behavior.” The Marine Mammal Center, 18 Feb. 2025. Accessed 8 Jan. 2026. The Marine Mammal Center

“Tips for Getting the Perfect Shot: Get Into Your Sanctuary!” NOAA National Marine Sanctuaries, 29 May 2021. Accessed 8 Jan. 2026. sanctuaries.noaa.gov

“Looking beyond the fog?” The Nautical Institute, 31 May 2024. Accessed 8 Jan. 2026. The Nautical Institute

Fishes of the Columbia River Estuary. StreamNet Library / CREDDP reference (PDF). Accessed 8 Jan. 2026. docs.streamnetlibrary.org

“Atmospheric and Hydrostatic Pressure” (training slides). NOAA Diving Center (PDF). Accessed 8 Jan. 2026. NOAA Marine Operati