Colorado River | smithsonianmag.comhttps://www.smithsonianmag.com/rss/tag/colorado-river/RSS feed for Colorado RiverenFri, 17 Apr 2026 19:11:08 +0000Scientists Still Don't Know How or When the Grand Canyon Formed. New Research May Hint at Its Ancient Originshttps://www.smithsonianmag.com/smart-news/scientists-still-dont-know-how-or-when-the-grand-canyon-formed-new-research-may-hint-at-its-ancient-origins-180988570/Researchers say the ancestral Colorado River formed an ancient lake in northern Arizona roughly 6.6 million years ago, which spilled out westward onto the landscape that would eventually become the Grand CanyonFri, 17 Apr 2026 19:11:08 +0000https://www.smithsonianmag.com/smart-news/scientists-still-dont-know-how-or-when-the-grand-canyon-formed-new-research-may-hint-at-its-ancient-origins-180988570/