Fossil Hunting in Montana
Montana is hallowed ground for dinosaur paleontology. More Tyrannosaurus rex specimens have been found in Montana than in any other state, and the Hell Creek Formation badlands around Jordan and Glasgow have produced some of the most important dinosaur discoveries in history.
Why Montana?
Montana’s eastern half is underlain by thick sequences of Late Cretaceous sedimentary rock deposited between roughly 80 and 66 million years ago — the final chapter of the Age of Dinosaurs. These rocks record the coastal plains, river deltas, and shallow seas that existed along the western shore of the great Western Interior Seaway.
Three formations dominate Montana’s dinosaur record:
- Hell Creek Formation (~68-66 million years ago): The youngest dinosaur-bearing formation in North America, deposited in the last two million years before the asteroid impact ended the Mesozoic Era. This is where T. rex, Triceratops, Edmontosaurus, and Pachycephalosaurus are found.
- Judith River Formation (~79-75 million years ago): Slightly older, with a different dinosaur fauna including early ceratopsians, hadrosaurs, and tyrannosaurs.
- Two Medicine Formation (~80-74 million years ago): Famous for Egg Mountain and Maiasaura nesting sites that revealed dinosaurs cared for their young.
The combination of arid climate, sparse vegetation, and ongoing erosion means new fossils are constantly weathering out of the badlands — but this also means the collecting landscape changes year to year.
What You’ll Find
Dinosaur fossils (Late Cretaceous, ~80-66 million years ago):
- Triceratops (Triceratops horridus and T. prorsus) — The most commonly found large dinosaur in the Hell Creek Formation. Horn cores, frill fragments, and teeth are the typical finds.
- Hadrosaurs (Edmontosaurus annectens) — Duck-billed dinosaur bones, teeth, and occasionally skin impressions.
- Tyrannosaurus rex — Isolated teeth are the most accessible find; skeletal material is rare but Montana has produced more T. rex skeletons than anywhere else, including the famous specimens “Sue” (found just across the border in South Dakota) and “B. rex.”
- Pachycephalosaurus — Dome-headed dinosaur skull caps are occasionally found in the Hell Creek.
- Thescelosaurus — A small ornithopod relatively common in the Hell Creek.
- Troodon — Small theropod teeth are distinctive with their large serrations.
Other vertebrate fossils:
- Crocodilian scutes and teeth
- Turtle shell fragments (very common)
- Champsosaur remains
- Gar scales and fish vertebrae
- Pterosaur bone fragments (rare)
Invertebrate and plant fossils:
- Ammonites and baculites in the Bearpaw Shale
- Freshwater bivalves and gastropods
- Leaf and stem impressions
- Petrified wood (sometimes beautifully colored)
Best Time to Visit
- Summer (June-September): The primary field season. Most organized dig programs run June through August. Montana’s remote eastern badlands are largely inaccessible in winter.
- After spring rains: Erosion exposes new material each year. Early summer is often the best time to spot freshly weathered-out fossils.
- Avoid spring mud season (April-May): The clay-rich bentonite soils of the Hell Creek Formation become impassably slick when wet. Gumbo roads can strand vehicles for days.
- Fall (September-October): Still warm enough for fieldwork, with fewer visitors. Some dig programs extend into early fall.
Tips for Montana Collecting
- Join an organized dig program. This is the most realistic way to find dinosaur fossils in Montana. The Museum of the Rockies, Montana Dinosaur Center, and several commercial paleontology outfits run multi-day excavation programs where paying participants work alongside professional paleontologists on active dig sites. These programs provide tools, instruction, and access to private ranch land.
- Bring everything you need. The Hell Creek badlands around Jordan are extremely remote. The nearest grocery store may be 60+ miles away. Cell service is nonexistent in many areas. Carry extra water, fuel, food, and vehicle supplies.
- Respect the gumbo. Hell Creek Formation clay (bentonite) is notorious. When wet, it becomes impossibly slick and sticky. A sudden rainstorm can make roads impassable. Check weather forecasts and carry traction aids.
- Watch for rattlesnakes. Prairie rattlesnakes are common in the badlands. Watch where you step and put your hands, especially around rock ledges.
- Understand the law. On private land, the landowner owns the fossils and can grant collecting permission. On federal land (BLM, Army Corps of Engineers), vertebrate fossils are protected by the Paleontological Resources Preservation Act and may not be collected without a permit. Invertebrate and plant fossils can be collected in reasonable quantities for personal use on most federal land.
- Report significant finds. If you find something that appears to be a significant vertebrate fossil (especially articulated bone or skull material), document it with photos and GPS coordinates and report it to the Museum of the Rockies or the relevant land management agency. You may be helping science — and some of Montana’s most important discoveries started as reports from amateur collectors and ranchers.
- Petrified wood and invertebrates are the accessible finds. If you’re visiting Montana without a dig program, beautiful petrified wood and Bearpaw Shale ammonites are more realistically found by casual visitors than dinosaur bone.
Collecting Sites
Hell Creek Area (Private Ranch Digs)
Private (Permission Needed)Jordan, Garfield County
The badlands around Jordan, Montana expose some of the richest Hell Creek Formation sediments in the world. Almost all land is privately owned ranches. Several outfitters and museums run supervised dig programs on private land where volunteers can participate in real dinosaur excavations. This is the formation that has produced more T. rex specimens than anywhere else on Earth.
Fort Peck Reservoir Area
Public (Fee)Fort Peck, Valley & McCone Counties
The shoreline and surrounding badlands of Fort Peck Reservoir expose Hell Creek and Bearpaw Shale formations. The Fort Peck Interpretive Center displays locally found dinosaurs. Collecting on Army Corps of Engineers land around the reservoir requires checking current regulations — surface collecting of invertebrates and common fossils is sometimes permitted, but vertebrate fossils are protected on federal land.
Egg Mountain / Choteau Area
Private (Permission Needed)Choteau, Teton County
Egg Mountain is the famous site where Jack Horner discovered Maiasaura nesting colonies in the Two Medicine Formation, revolutionizing our understanding of dinosaur behavior. The site is on private land managed by Montana State University. Public access is through organized field programs run by the Museum of the Rockies.
Makoshika State Park
Public (Fee)Glendive, Dawson County
Montana's largest state park exposes dramatic Hell Creek Formation badlands. Triceratops skulls and hadrosaur bones have been found here. Collecting is NOT permitted within the park, but it is an excellent place to see Hell Creek geology and fossils in context. The visitor center has a small but excellent fossil display.
Judith River Formation Exposures
Private (Permission Needed)Havre area, Hill County
The Judith River Formation along the Missouri River breaks north of Havre contains diverse Late Cretaceous dinosaur and marine fossils. This formation is slightly older than the Hell Creek (~75 million years ago). Access is primarily through private ranches — the Montana Dinosaur Center in Bynum runs field programs in this area.
Legal Rules for Montana
Montana follows federal PRPA rules on federal land (BLM, National Forest, Army Corps): vertebrate fossils cannot be collected without a permit, but invertebrate and plant fossils may be collected in reasonable quantities for personal use. State land follows Montana state regulations — vertebrate fossil collecting requires permission from the relevant state agency. Most productive dinosaur-bearing land in Montana is privately owned ranch land. Private landowners own the fossil rights on their property and can grant permission to collect. Always get written permission. Several commercial operations and museums run legitimate paid dig programs on private land. Never collect in Makoshika State Park, national monuments, or other protected areas.
Read our full legal guide for federal laws and more details.
Key Geological Formations
- Hell Creek Formation (Late Cretaceous)
- Judith River Formation (Late Cretaceous)
- Two Medicine Formation (Late Cretaceous)
- Bearpaw Shale (Late Cretaceous)
- Morrison Formation (Late Jurassic)
Local Fossil Clubs & Museums
- Museum of the Rockies
- Montana Dinosaur Center
- Great Plains Dinosaur Museum
- Carter County Museum
- Makoshika Dinosaur Museum