This word is great for headlines, but bad science. We're uncovering tiny fragments of a vast history and extrapolating the full story as best we can from those few clues we have. We can't ever be sure we're right, only that we're maybe a little more right than before. Next week, someone will find a new piece of evidence that could rewrite the entire story all over again (wow, the Beringians had dogsleds and could cover fifty miles per day over snow?).
And this matters in science writing because the general public see words like "show" and "proves" and take it as truth, unbreakable. And next week when we find that new piece of evidence, that article will use the same strong terminology and the reader who isn't science literate will lose trust in science- last week they said X was true, now they say Y is true? Are they lying or making this all up?
Nothing is certain. We're just trying to be less wrong over time.
I made that fact up, so that we're all clear here- dogs weren't even domesticated that far back. But hey, what if, right?
Here is a link to a National Geographic article that goes a bit further with the story including showing a map of the general area of the archaeological site. It also includes a photo of the actual dig site as seen from a high point on the canyon downstream. As you can see from the photo, the site is right on the river at the mouth of the canyon that runs roughly south out of Cooper's Ferry to the river.
I don't know why CNN didn't link any actual published material about the site, choosing instead to link to random unrelated stuff.
I visited this site back in 2011 while rafting the Salmon with my family. Back then they were carefully sifting, cataloging, etc., all the things they were finding. They had a pretty enthusiastic group of students carefully excavating.
This is a photo I took while we toured the site. Our guide knew the river and everyone working on it and made arrangements for us to have a brief visit. Wapiti River Guides out of Riggins, Idaho.
The site that others have mentioned in Texas is actually very near our old family land in Central Texas. You never had any trouble collecting arrowheads or spearheads in that area. Limestone outcrops with extensive chert nodules likely made it a popular place for early humans to visit and fashion tools and that chert was widely traded elsewhere.
It's actually been longer than that. The site at Monte Verde  in Chile seems to have been widely accepted as a pre-Clovis site nearly 20 years ago (1997 according to Wikipedia ). Awareness of the site, at least among the archaeological community predates that (1989 ). The first radiocarbon dates indicating a pre-Clovis origin for the site go back to 1982.
The idea that Clovis was not the earliest culture in the Americas, and the commensurate theory that the earliest colonists must have been traveling by boat  goes back decades. I know I've been reading about it (in the popular press no less) since the 1990s. It seems like every article I read about it makes it seem like some new and revolutionary idea. The only conclusion I can draw is that archaeological science operates on time scales only slightly shorter than those the archaeologists study.
 https://en.wikipedia.org/wiki/Monte_Verde#Discovery (third paragraph)
 I'd like to give you a citation for this, but this theory, as far as I can tell has no official name.
[Just quoting myself from https://news.ycombinator.com/item?id=12603556]
"The coastal migration hypothesis" - https://en.wikipedia.org/wiki/Coastal_migration_(Americas), which should not be confused with "the Southern Dispersal scenario (also the coastal migration hypothesis)" at https://en.wikipedia.org/wiki/Southern_Dispersal.
Earlier groups did not necessarily have their technological sophistication, nor their cultural and technical mastery of the ocean, so its misleading to argue via analogy.
 A kayak is really a marvel in terms of engineering the most with the absolute least amount of materials, even modern materials and techniques are hard pressed to match a traditional design, particularly with the outer skin, animal skin is much lighter, quieter, more durable and repairable than something like fiberglass. Each boat is carefully fitted to its owner, and designed precisely for maximum agility and stability.
instead of going farther up the Columbia. Might not have been a viable option!
"On the western edge at the Haida Gwaii ... the lower thickness of the ice sheet meant that sea levels were as much as 170 metres lower than they are today.... migrants ... were able to travel southward during the deglaciation process due purely to the exposure of submerged land between the mainland and numerous continental islands...."
That seems like a logical jump. (Not familiar with the accuracy of radiocarbon dating, please educate me.)
> But to verify, he'll have to do a little more digging.
Portland Oregon and Sapporo have had a sister-city relationship for about sixty years. It would be an interesting coincidence if it turned out that their native inhabitants were more closely related than previously thought.
That said, I'm always extra cautious with claims out of Idaho and Utah given the density of people with very high desire to find ancient civilization. Eg the ongoing search and occasional "Discovery" of Nephilim Giants.