• Massive petrified redwood stumps

    Florissant Fossil Beds

    National Monument Colorado

Introduction (Unit 1) - Eocene Florissant

Timeline of Florissant Fossil Beds
Eocene Florissant

Eocene Florissant

The uplift of the Rockies had began during the late Cretaceous and by the late Eocene, the region had low to moderate relief. During the late Eocene (36.7 million years ago), volcanic activity increased, beginning with an enormous eruption near present-day Mount Princeton. This eruption blanketed the area with the Wall Mountain Tuff as far away as 150 kilometers (93 miles). Imagine a superheated cloud of ash, rocks, mineral crystals, glass, and debris moving at speeds of up to 100 miles per hour. Two million years later, near the town of Guffey, Colorado a cluster of large stratovolcanoes developed sending ash and lahars into the area. It was this highly active volcanic period that helped to create the ancient Lake Florissant.

Pleistocene Florissant

Did You Know?

Photo of 14 foot wide, 12 foot tall petrified tree stump of a redwood

The massive petrified redwood stump known as the "Big Stump" is not actually the largest diameter stump at Florissant Fossil Beds. The "Big Stump" measures 38 feet in circumference, but the biggest stump is over 41 feet.