Dinosaurs used to live here but you would be hard pressed to see any evidence of them. As a group, they are mostly romanced by children but some of us never really grow up. I spend a great deal of my spare time “climbing stairs” around the local hills looking for the evidence of their passing this way. It helps me stay in shape as climbing around outcrops really gets the ticker racing.
In some places around Montana, dinosaur fossils lay about as so much detritus on the surface, As such, the remains are often ignored by the locals. Around Powder River country, most of the clues that they left are very subtle. There are not piles of fossil bone just laying about for the casual hiker to pick up and take home to lay around the garden. In badland country, soil moves quickly away such that any fossil is quickly exposed. The grass here however, has effectively slowed the rate of soil removal and subsequent bone exposure. Fossil bone material usually decays into dust when acted upon for long periods of time by soil acids. So grass by it’s nature prevents fossils from surviving, being exposed and finally discovered. Because of this, we are not known as the Dinosaur capital of the world.
We could be one of the dinosaur hot spots of the globe if everyone knew what to look for and where to look. Fossils are everywhere in Powder River County, they are just tricky to find. VERY GENERALLY, it can be said that any rocks to the west of highway 59 are younger than the dinosaurs but rocks, just to the east are about right. Three things control the occurrence of dinosaur fossils: the thickness of the Hell Creek Formation (Dinosaur fossil bearing) the elevation of the topography, and the regional dip of the rocks. Certainly gullies expose bedrock and they are a likely place for fossils to be found. (Watch out for other things that hang out in gullies too like bulls, rattlesnakes and really big kitties). The Hell Creek Formation may be up to 700 feet thick around here so there is a variable swatch of exposure on the map that runs from Hammond all the way down to Newcastle Wyoming (Hell Creek Formation is called Lance Formation in Wyoming). This band ranges up to 14 miles wide at times.
Too high, or too low, too far east or too far west and you are out of luck if it is dinosaurs you seek. To the east of the Hell Creek formations exposure will be marine fossils with only rare marine dinosaurs possible. To the west, mammal fossils along with crocodiles, turtles and various other more modern types are abundant but no dinosaur remains are present. The trick is to keep your eyes to the ground, know where you are and be aware of things that don’t belong. Rock outcrops are common everywhere but fossils may only be on the surface on some of them. I often use the “look” of a sand bed to determine where to dig. This feeling is developed by many years of hunting fossils.
Things to look for include, shiny black enamel gar pike fish scales (easy to see and a sign that says dig here), sand with muddy pebbles mixed in (often not exposed on the surface but will be just under a thin weathered coat of sand) which you have to rake away to see the pebbles. This sand/muddy pebble mix is the best sediment to find a large variety of dinosaur fossil material. This material was laid down in the center of a river during a flood event which washed the dried mud off a mud flat (along with any piece of bone or teeth that was lying about). This type of deposit is called a microsite because they usually don’t contain complete dinosaur remains but can contain almost anything else but usually has small fossils. These may include: salamander, fish, turtle, frog, reptile, dinosaur, mammal, and alligator bone/teeth/claws/parts.
Remember that fossils belong to who owns the land. That includes the federal or state governments. It is illegal to take fossils from government lands. Private lands can be searched with permission to access but make sure to discuss who owns what if you discover the tip of the tail of the complete T-Rex. If you think you have important fossil remains on your ranch, I would be tickled to get involved but be warned that if you have something important, a museum or university will follow up with the collection. You may get a big tax deductible donation, I will get a free education, and the institution will get a nice display to study and learn the past from. A win, win, win situation. More about dinosaurs later.