Paper in Science: https://phys.org/news/2026-04-colorado-river-geological-mill...
An upstream river, followed by flowing into the Grand Canyon, thus becoming a continental river. Saved you a click. It’s still a cool read though.
Was it buried under popup advertisements?
The original title (which makes a lot more sense than the abbreviated one used for the submission):
> The Colorado River disappeared from the geological record for 5 million years: Scientists now know where it went