Fossil Hunting in New Mexico

intermediate friendly BrachiopodsCrinoid stemsShark teethAmmonitesDinosaur tracks

Why New Mexico?

New Mexico sits at a geological crossroads. Permian marine deposits from an ancient tropical sea are spectacularly exposed in the southeast near Carlsbad. Cretaceous Western Interior Seaway sediments cross the state, yielding ammonites and shark teeth. The Kirtland and Fruitland formations in the San Juan Basin have produced important dinosaur finds. Clayton Lake State Park preserves one of the finest dinosaur trackway sites in the Southwest. The arid climate means excellent exposure and year-round accessibility.

What You’ll Find

Permian brachiopods, crinoid stems, fusulinids, and bryozoans are abundant in the limestones of the Guadalupe Mountain foothills. Cretaceous marine fossils, including ammonites, inoceramid bivalves, and shark teeth, occur in the Mancos Shale exposures across central and northern New Mexico. Dinosaur tracks at Clayton Lake represent multiple species including ornithopods and theropods. Petrified wood is scattered across several parts of the state. Vertebrate fossils from the San Juan Basin are scientifically important but off-limits to casual collectors.

Best Time to Visit

Fall and spring are ideal. October through November and March through May offer comfortable temperatures and clear skies. Summer brings intense heat in the lowlands and afternoon thunderstorms. Winter is mild in the south but cold in the northern mountains. The desert can have extreme temperature swings between day and night.

Tips for New Mexico Collecting

Land ownership in New Mexico is complex. Large areas are BLM, national forest, tribal, or military land, each with different rules. Always verify land status before collecting. The Guadalupe Mountain foothills on BLM land east of Carlsbad are productive and legal for invertebrate collecting. Near Albuquerque, Cretaceous exposures along the Rio Grande valley are accessible. Clayton Lake is well worth the drive to northeast New Mexico for the trackways, but is viewing only. Carry ample water, sun protection, and watch for rattlesnakes in rocky terrain.

Collecting Sites

Cerrillos Hills area

Free Public Access

Cerrillos, Santa Fe County

Cretaceous marine sediments exposed in the hills south of Santa Fe yield Western Interior Seaway fossils.

Shark teethAmmonitesBivalves

Guadalupe Mountains foothills

Free Public Access

Carlsbad, Eddy County

Permian reef and shelf limestones with abundant marine invertebrate fossils. BLM land offers collecting on the New Mexico side of the Guadalupe range.

BrachiopodsCrinoid stemsFusulinidsBryozoans

Clayton Lake State Park

Public (Fee)

Clayton, Union County

Over 500 dinosaur tracks from at least eight species preserved in Cretaceous lake shoreline sediments. Viewing only; no collecting.

Dinosaur tracks

Legal Rules for New Mexico

BLM land in New Mexico allows casual collecting of reasonable amounts of invertebrate and plant fossils for personal use. Vertebrate fossils on federal land require permits. State parks prohibit collecting. National monuments and parks (including Carlsbad Caverns) prohibit all collecting. Much of New Mexico is BLM or tribal land; verify land status carefully.

Read our full legal guide for federal laws and more details.

Key Geological Formations

Mancos Shale (Cretaceous)
San Andres Formation (Permian)
Carlsbad Group (Permian)
Kirtland Formation (Late Cretaceous)
Abo Formation (Permian)