50 million years ago, a subtropical forest thrived in what is now the Gallatin Range of Montana. Towering trees, ferns, and prehistoric creatures lived in a warm, humid climate—until catastrophe struck. A massive volcanic eruption from the Absaroka Range unleashed lahars—deadly mudflows of ash, rock, and debris that surged down the mountainsides like wet concrete. These torrents entombed everything in their path, including entire forests. Some trees were petrified, their organic matter replaced