Florissant Formation

The Florissant Formation is a sedimentary geologic formation outcropping around Florissant, Teller County, Colorado. The formation is noted for the abundant and exceptionally preserved insect and plant fossils that are found in the mudstones and shales. Based on argon radiometric dating, the formation is Eocene (approximately 34 million years old ) in age and has been interpreted as a lake environment.

The fossils have been preserved because of the interaction of the volcanic ash from the nearby Thirtynine Mile volcanic field with diatoms in the lake, causing a diatom bloom. As the diatoms fell to the bottom of the lake, any plants or animals that had recently died were preserved by the diatom falls. Fine layers of clays and muds interspersed with layers of ash form "paper shales" holding beautifully-preserved fossils.

The Florissant Fossil Beds National Monument is a national monument established to preserve and study the geology and history of the area.

Florissant Formation occupies a particular place in the imagination of American public lands. As a Park Unit in Colorado, it represents a deliberate choice — by the people who advocated for its protection, and by the National Park Service rangers who maintain it — to keep this landscape available to anyone willing to make the trip. That accessibility is the quiet miracle of the park system.

The pages linked below break the visit down into the four practical questions every traveler asks: where can I hike, where can I sleep, what else is worth seeing while I'm in the area, and what should I know before I show up. Each one is written from the perspective of someone planning their first trip — assume nothing, explain what's worth explaining, and skip the marketing language. If you've been here before, treat these guides as a refresher and a way to discover the corners you missed last time.

What this guide covers

Over the next four pages, this field guide breaks Florissant Formation into the practical questions every traveler asks: which trails are worth the effort, where to sleep both inside and outside the park boundary, what else is worth a stop in the surrounding region, and the small-but-essential tips that make the difference between a stressful first day and a smooth one. Use the navigation above to jump between sections, or read them in order — they're written to flow.

• Hikes — short loops, half-day trails, and backcountry routes
• Camping — drive-in campgrounds, RV sites, and backcountry permits
• Nearby attractions — gateway towns and adjacent public lands
• Visitor tips — timing, fees, weather, and what to skip

Logistics at a glance

Use this quick reference when you're putting together your itinerary. The figures below are the most-asked questions every visitor needs answered before arrival, summarized in one place.

Designation	Park Unit
State	Colorado
Entrance fee	Varies — check the official park site below for current rates.
Visitor center hours	Most open daily 8–9am to 4:30–6pm. Reduced winter hours common.
Best months	Plan around the weather notes above.
Camping inside park	See the camping guide for campground details, fees, and reservation windows.
Nearby gateway towns	See nearby attractions for lodging and supply stops.