“Almost everywhere you look, with every step you take, the canyon seems intent on pulling you further into the past,” Mathieu said one afternoon in reference to the relics in those limestone caverns, all of which belonged to prehistoric creatures that had inhabited the abyss prior to the end of the last ice age, between ten thousand and forty thousand years ago. “Everybody focuses on the ages of the rock layers, which are calibrated in tens of millions of years, but there are lots of other things that can add depth and richness to your understanding of how time works in this landscape.”
