Related: These clues suggest that Hells Canyon formed when water diverted from Lake Idaho into the current route of the gorge to form what's now the Snake River. The lake may have spilled over ...

More information: Matthew C. Morriss et al, Cave records reveal recent origin of North America's deepest canyon, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2413069122 ...