Yellowstone lake mud preserves a 15,000-year record showing how drought, wildfire and underground heat changed the landscape. Lodgepole pine forests stayed surprisingly stable, while fires increased sharply during hotter, drier periods. Wetter conditions strengthened hydrothermal activity, suggesting future drying could affect geysers while increasing wildfire risk. Yellowstone’s steaming geyser basins may look timeless, but lake mud tells a different story. A new study shows that climate, wildfire and underground heat have shaped the Yellowstone Plateau for 15,000 years. The National Science Foundation-funded research was led by Cathy Whitlock, a Montana State University Regents Professor emerita of earth sciences. By studying sediment cores from small lakes in Yellowstone National Park’s Lower Geyser Basin, scientists reconstructed the region’s long environmental history. The layers revealed changes in vegetation, fire, lake chemistry and hydrothermal activity since the last ice age. A Landscape Written In Lake Mud Whitlock has spent decades studying the Greater Yellowstone Ecosystem. Her work often begins with lake sediment, which stores tiny clues year after year. Maps showing locations discussed in text. (CREDIT: Proceedings of the …