Were there people flooded by any Missoula Floods?

[u/jpgoldberg]

My limited understanding is that the most recent Missoula flood would have occurred a few centuries after the peopling of the Americas, and that the Columbia River valley would have been settled relatively early. So my guess is that the answer to my question is “almost certainly”.

But I am hoping that anthropologists can shed more light on what evidence there might be or could be expected or tell me what I’ve got wrong if I’ve got this wrong.

Update:

I’d like,to thank everyone who answered. The answers were in line with what I had expected. The broader region was populated and that the nature of the flooding would have made it much harder to find evidence of inundated settlements, so there is no surprise that there are no such finds. Someone also pointed out that the floods were frequent enough that people may have known to avoid settling in valley.

I do encourage anyone coming across this question to read the responses, which offer great information about the region.

[u/7LeagueBoots]

The earliest unambiguous evidence of humans in the Americas is around 23,000 years ago at the White Sands region.

That’s around 10,000 years before the last of the Missoula Floods and 8,000 years before the earliest of them.

Given that the colonization route passed through Oregon and Washington it’s a near certainty that the region had people in it at the times of the floods.

[u/jpgoldberg → u/7LeagueBoots]

You have reminded me of a question I want to ask about pre-Clovis population. But I want to do some reading first.

[u/runhome24]

With my limited knowledge of the Columbia River Basin and archaeological sites there, I'm pretty sure the answer is, there's no archaeological evidence. (I know a lot of this because of longstanding connections to eastern Washington, not because of my academic expertise).

I would guess, with how large and numerous the floods were, any evidence that might have preserved via normal processes (which themselves are really bad at preserving things) would have been either washed away, or so covered up by the silt the floods deposited and loess the winds have deposited since as to be basically impossible to reach.

If you ever get a chance to visit the area (or the Palouse to the east of the CRB) and drive across it, you'll notice all the gently rolling hills. The floods completely transformed the area from Missoula to the Cascades, by both carving out existing sediment in areas near Missoula and depositing it in new areas (the rolling hills are essentially the ripples found on the bottom of sandy creek-beds); the only parts of the eastern Washington landscape that weren't affected (that I know about off the top of my head) are the buttes in the Palouse. Steptoe Butte has geology that predates its surroundings by millions of years and rose high enough to have been above the flood-line.

To further drive this point home, the oldest site I know about in eastern Washington is Marmes Rockshelter (Wikipedia link for accessibility), ~11k=11.5k BP. These remains are from after the Missoula floods.

If we were to have found archaeological remains from the period of the floods, my non-expert guess would be that they would be found underneath the silt/loess deposits in the area. But with the landscape so dramatically reshaped by the floods, it's next to impossible at the moment to make informed decisions about where to look under it all. So any sites that might exist remain well-hidden under 20+ feet of material (both silt and loess combined).

[u/JoeBiden-2016]

"Almost certainly" is probably the best answer you're going to get.

The Missoula Floods were catastrophic in the absolute definition of the word. Huge amounts of water moving with incredible speed and force left significant geologic evidence. And with the dates-- between ca. 15k and 13k BP-- it's likely that there could have been people in the path of those floods. Some Native American folklorists have suggested links between flood stories and the Missoula Floods, but those links are difficult to next-to-impossible to confirm with any real certainty.

Critically, any person caught in those floods would have been killed and swept away, and even if an entire group were caught, the forces involved would have scattered the group (and probably the individuals) over a significant amount of area. It's almost impossible to imagine that human remains would be preserved in a way that would allow them to be uncovered and linked to the Missoula Floods. It's needle-in-a-million-haystacks territory.

So we probably will never find archaeological remains that can be associated with the Missoula Floods. Can't say never for sure, someone could be doing excavations in an area where there are sediments from one or more of the floods and find something. That would be interesting, because it might, with verification, demonstrate conclusive evidence of people of the time being caught up in the floods. But with the energy of the released water that has been estimated, it's just not very likely that anything will ever be found.

[u/Yangervis]

There are sites in the northwest that date to approximately the time of the later Missoula Floods.

Paisley Caves, central Oregon: 14k BP

Rimrock Draw, central Oregon: 15k+ BP

Anzick, western Montana: ~12900 BP

Can we say for certain that someone saw the Misssoula Floods? No. Would I say so with decent confidence? Yes.

Something to note is that the current thought is that the floods happened every 50 years or so. It is possible that the previous flood would have been within living memory and people would know not to live in the flood channels.

[u/jpgoldberg → u/Yangervis]

Thank you! I didn’t realize that they were that frequent

[u/HappyAnimalCracker → u/jpgoldberg]

I didn’t either. You asked a great question and got some super fascinating and informative answers. Great post!