Fossil Hunting in California

California may be best known for earthquakes and gold, but the Golden State also harbors some of North America’s most significant fossil sites. From the staggering Miocene bone bed at Sharktooth Hill to the Pleistocene megafauna trapped in the La Brea tar pits, California’s paleontological heritage spans hundreds of millions of years and both marine and terrestrial ecosystems.

Why California?

California’s complex tectonic history has created an extraordinary geological mosaic. The collision of the Pacific and North American plates, the opening and closing of seaways, volcanic activity, and dramatic sea-level changes have all left their mark in the rock record.

During the Miocene epoch (23 to 5 million years ago), California’s coast was home to a rich marine ecosystem. Sharks, whales, sea cows, and pinnipeds (seals and sea lions) thrived in warm Pacific waters. The Round Mountain Silt at Sharktooth Hill near Bakersfield preserves one of the densest concentrations of Miocene marine fossils anywhere on Earth — the bone bed contains an estimated 200 specimens per square meter.

During the Pliocene and Pleistocene (5 million to 11,000 years ago), California’s inland valleys and deserts supported an incredible megafauna: horses, camels, mammoths, saber-toothed cats, dire wolves, and giant ground sloths. The Anza-Borrego Desert preserves this record in spectacular badlands exposures, and the La Brea Tar Pits captured a snapshot of Ice Age Los Angeles in astonishing detail.

Collecting opportunities in California are more limited than in states with vast BLM land, because many of the best sites are in state parks (no collecting) or on private land (access through operators only). But for the dedicated collector, there are still productive spots on BLM land, along public coastlines, and through organized commercial digs.

What You’ll Find

Miocene marine fossils (~23-5 million years ago):

• Shark teeth — dozens of species at Sharktooth Hill, including ancestors of the great white, giant mako teeth, and occasional Otodus megalodon teeth up to 5+ inches
• Marine mammal bones — whale vertebrae, rib fragments, dolphin teeth, pinniped bones, and the enigmatic Desmostylus (a hippo-like marine mammal now extinct)
• Ray dental plates — from eagle rays and other species
• Fish fossils — whole body impressions in Monterey Formation shale, individual teeth and vertebrae in the Round Mountain Silt
• Gastropods and bivalves — turritella, pecten scallops, and other Miocene mollusks

Pleistocene megafauna (~2.5 million - 11,000 years ago):

• Smilodon fatalis (saber-toothed cat) — California’s state fossil, best known from La Brea
• Dire wolf (Aenocyon dirus) — the most commonly found large mammal at La Brea
• Columbian mammoth (Mammuthus columbi)
• Western horse (Equus occidentalis)
• Yesterday’s camel (Camelops hesternus)
• Harlan’s ground sloth (Paramylodon harlani)
• American lion (Panthera atrox)

Pleistocene marine invertebrates:

• Uplifted marine terraces along the coast, particularly at Palos Verdes and near Santa Cruz, contain gastropods, bivalves, and barnacles from Pleistocene shallow seas

Best Time to Visit

• Fall and winter (October-March): Best season for Sharktooth Hill digs — cooler temperatures make the Kern County heat manageable. The organized digs typically run from October through May.
• Spring (March-May): Excellent for Anza-Borrego wildflower season, which can be combined with paleontology hikes. Coastal collecting is good year-round but spring offers pleasant weather.
• Low tide periods: For coastal fossil hunting at Palos Verdes, Jalama, or other beach sites, check tide charts and visit during minus tides for maximum rock exposure.
• After winter storms: Pacific storms erode coastal bluffs and wash new material onto beaches. The days immediately following a major storm are prime collecting windows.
• Avoid summer in inland valleys: Bakersfield and the desert areas regularly exceed 110 degrees F in summer. Heat exhaustion is a serious risk.

Tips for California Collecting

1. Book a Sharktooth Hill dig in advance. The bone bed is on private land and can only be accessed through organized digs, primarily run through the Buena Vista Museum of Natural History and the Kern County Fossil Preservation Society. These sell out — plan ahead.
2. Understand state park rules. California state parks strictly prohibit fossil collecting. At Anza-Borrego, enjoy the fossils in place, photograph them, and report significant finds to park paleontologists. Violating these rules carries real fines.
3. Visit La Brea for inspiration, not collecting. The Tar Pits museum is one of the best paleontology museums in the world. Watching researchers clean and catalog specimens in the fishbowl lab is unforgettable.
4. Try coastal beach hunting. Loose fossils in beach gravel below the high-tide line on public beaches can generally be collected. Palos Verdes, Capitola, and certain Santa Barbara County beaches yield Pleistocene and Miocene invertebrates and occasional bone fragments.
5. Never dig into coastal bluffs. California’s sea cliffs are unstable and prone to sudden collapse. People have been killed by cliff falls. Collect only from material already on the beach.
6. Bring sun protection and plenty of water. Whether at Sharktooth Hill, in the desert, or on the coast, California sun is intense. Hat, sunscreen, and hydration are essential.
7. Check BLM land for open collecting areas. The Calico Mountains, parts of the Mojave, and other BLM-managed lands allow casual invertebrate and plant fossil collecting. The BLM California office website has maps and current information.
8. Join the Kern County Fossil Preservation Society. If you are serious about California fossil collecting, KCFPS membership provides access to Sharktooth Hill digs, field trips to other sites, and a community of knowledgeable collectors.

Collecting Sites

Legal Rules for California

Key Geological Formations

• Round Mountain Silt (Miocene)
• Monterey Formation (Miocene)
• Palm Spring Formation (Pliocene-Pleistocene)
• La Brea Tar Pits (Pleistocene)
• Modelo Formation (Miocene)

Local Fossil Clubs & Museums

• Kern County Fossil Preservation Society (KCFPS)
• Buena Vista Museum of Natural History
• San Diego Natural History Museum
• Natural History Museum of Los Angeles County
• Los Angeles Paleontological Society
• Northern California Geological Society