Evidence of Flooding in Cliffside Caves

56,000 years ago, a 600,000,000-pound asteroid hit Earth, creating Meteor Crater in Arizona. The same nickel-iron asteroid, may have also formed a temporary lake, in the Grand Canyon. Researchers believe the impact caused an earthquake, triggering a rockslide that dammed the Colorado River. Driftwood accumulated in caves, before the water eventually dropped back down.