Florissant Formation Park

Florissant Formation is a geological and palaeontological unit in central Colorado, United States, famous for late Eocene (about 34 million years old) fossil deposits. The formation is best known for finely laminated shales that preserve detailed plant and insect compression fossils.

The site yields large numbers of fossil insects, leaves, and other terrestrial organisms that inform reconstructions of Eocene terrestrial ecosystems and climate. Fossils from the formation have been studied since the 19th century and continue to be important for palaeobotany and paleoentomology.

Work that exposed and described the Florissant fossils occurred in the 19th and 20th centuries; important collections are held by museums and a nearby national monument protects significant outcrops and provides public interpretation. The formation occurs near the modern town of Florissant in the foothills of central Colorado, set among forested terrain and volcanic-capped ridges.

• Age: The deposits are late Eocene in age, roughly 34 million years old, and preserve exceptionally detailed plant and insect fossils.
• Preservation: Fine-grained shales in the formation are the reason for the high-quality preservation of wings, leaves, and other delicate structures.

What to See#

• Fossil beds: A fossil-bearing sequence of fine-grained shales and mudstones that preserve delicate compression fossils of plants and insects dating to the late Eocene.
• Visitor displays: A visitor area and interpretive displays at the protected national monument that explain the palaeoenvironment and show representative specimens found in the formation.

The Florissant Fossil Beds National Monument lies near Florissant, Colorado, about 40 minutes west of Colorado Springs via US‑24 and CO‑24; local signposting leads to the park’s visitor center and trailheads.

• If interested in fossils, contact local universities or visitor centers for guided paleontological hikes and permissions.
• Bring sun protection and water-exposures on the high plains can be intense.
• Check with Colorado state or local authorities for any trail access restrictions; some areas are protected research sites.