Grand Canyon eruptions
Between 1.25 million BC and 250,000 BC, scientists believe there were 13 major volcanic eruption periods in the Grand Canyon.
Because the water levels were lower due to the Ice Age, the continents experienced dust storms.
No Great Lakes
The five Great Lakes — Superior, Huron, Michigan, Ontario, and Erie — form the largest interconnected body of fresh water on Earth, but they didn’t exist a million years ago because of the ice sheet that covered much of Canada and the northern United States.
One million years ago, there were large freshwater lakes in what is now the western United States — Bear Lake on the Utah-Idaho border; Utah Lake near what is now Provo, Utah; and Lake Bonneville, which eventually formed the Great Salt Lake, the biggest inland body of salt water in the Western Hemisphere
Florida’s size fluctuated
Throughout most of its history, Florida has been underwater. However, during periods of glaciation, the peninsula would have expanded. When the sea level was at its lowest, Florida’s western coastline was probably 100 miles farther out than where it is today.