Scientists in Wyoming have uncovered evidence of two ancient volcanic eruptions older than Yellowstone’s last supereruption, which occurred 631,000 years ago, during a field trip to the Lava Creek Tuff. The ash deposits, buried beneath the Tuff, suggest prior eruptions, potentially linked to the Bishop Tuff eruption in California, while the origin of the older deposit remains unknown. Test results expected by summer 2025 will provide clarity on the deposits’ ages and origins, revealing insights into volcanic activity in the region.