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Since the 1990s, various paleontological surveys have been conducted in Curecanti. Most of the paleontological resources at Curecanti are from the Jurassic, Cretaceous, and Pleistocene-Holocene periods. These include fossil plants, invertebrates, vertebrates, and trace fossils. These fossils are part of the park and surrounding area’s geologic story. Changing reservoir levels and annual runoff cause weathering an erosion. This leads to an increased concern for the preservation of paleontological resources. The following laws protect all fossil found in national parks. Please leave everything you find as it is. 
NPS Types of FossilsBecoming a fossil is rare. Fossils require ideal conditions, such as being buried or living in water. Paleontologists find more fossils of small marine organisms instead of larger mammals or dinosaurs.Vertebrate FossilsVertebrate fossils are parts of the body of anything with a backbone (bones, teeth, armor, soft tissue impressions). This includes the dinosaurs that called this area home long ago. Most dinosaur fossils are found where ancient rivers, lakes, and swamps were. Water was able to move enough sediment to bury the dinosaur remains - therefore beginning the fossilization process. Dinosaur, reptile, amphibian, bird, and mammal bones have been found at Curecanti from the Jurassic to Pleistocene-Holocene.Plant FossilsPlant fossils can include flowers, trees, stumps, leaves, roots, nuts, cones, needles, stems, twigs, seeds, and pollen. Fossil wood, plant fragments, leaf impressions, and root traces have been found in different sandstone formations at the park.Invertebrate FossilsInvertebrate fossils are fossils from organisms without backbones or a segmented spinal column. This includes animals with internal or external shells, snails, insects, and spiders. These types of fossils are the most encountered in national parks. Curecanti has invertebrate fossils from both the Jurassic and Cretaceous periods.Trace FossilsTrace fossils are traces of something an animal or plant did during its life. These behaviors or activities are like snapshots of how the animal or plant lived. These types of fossils include footprints and trackways, burrows, marks from feeding, scat (coprolites), and even diseases. There have been a root traces and burrows found at Curecanti.Fossil Record at CurecantiAlthough some formations may not contain paleontological resources at Curecanti, there may be examples found in the same layer at other national parks. Due to the terrain being heavily eroded, covered with thick vegetation, or impacted by the creation of Blue Mesa Reservoir, some typically fossil rich formations cannot be surveyed to the greatest extent.PrecambrianThe oldest exposed rocks at Curecanti are Precambrian metamorphic and igneous rocks. It is hard to tell what the paleo-environment was like from metamorphic rocks, since they have been changed dramatically over time. These metamorphic processes can squish or destroy fossils. This makes fossils unlikely to be found.Middle JurassicThe environment during the Middle Jurassic ranged from a desert with large sand dunes to something more marine-like. Entrada Sandstone, a fine to medium coarse-grained sandstone, is from this age. In sandy deserts, bones break down quicker, and wind sweeps away footprints. The Wanakah Formation includes more siltstone and mudstone with fine grained cross bedding. This aligns more with the marine depositional environment. This formation is not famous for fossils. However, some invertebrate burrows and a plant mold have been found along the North Rim Road. 
NPS Middle JurassicThe environment during the Middle Jurassic ranged from a desert with large sand dunes to something more marine-like. Entrada Sandstone, a fine to medium coarse-grained sandstone, is from this age. In sandy deserts, bones break down quicker, and wind sweeps away footprints. The Wanakah Formation includes more siltstone and mudstone with fine grained cross bedding. This aligns more with the marine depositional environment. This formation is not famous for fossils. None have been found at Curecanti. Late JurassicThe Morrison Formation at Black Canyon and Curecanti is divisible into members, such as the Salt Wash and Brushy Basin members. These date back between 155 and 148 mya. This formation is well-known for its fossils. Large dinosaurs such as Allosaurus, Apatosaurus (often called "Brontosaurus"), Brachiosaurus, Diplodocus, and Stegosaurus are well known from the Morrison. Outcrops of the Morrison Formation can be difficult to access due to terrain or being now underwater. Despite this challenge, many vertebrate and invertebrate trace fossils have been found. 
NPS Early to Late CretaceousBurro Canyon Sandstone, Dakota Sandstone, and Mancos Shale are all formations from the Early to Late Cretaceous. The Burro Canyon Sandstone has no recorded fossils in the park.The Dakota Sandstone is made up of sandstone and shale. It is more erosion resistant than the Mancos Shale. Fossils in this formation are diverse due to a variety of deposition across environments. Plant fragments, wood, molds of plant and invertebrate fossils, and invertebrate burrows have been found in the park. Late CretaceousMancos Shale is a clay-rich shale layer with some sandstone and siltstone. It is known for being rich in marine fossils across the Colorado Plateau, even with how fast it breaks down. Within the park, bivalves (clams, oysters, and ammonites), plant fragments, invertebrate traces and fragments of fish have been found.Stratigraphy and Fossils ChartSome formations/rocks are included to show areas where fossils are improbable or have not found in the park.
More on Geology and Fossils
Geologic Story
Read the chapters that make up the geologic story of Black Canyon and Curecanti. 
Fossils at Black Canyon
Similar rock formations exist at Black Canyon. Learn about their fossil plants, invertebrates, vertebrates, and trace fossils. 
Become a Junior Paleontologist
Explore the ways that paleontologists work, learn about ancient plants and animals, and help protect park resources like fossils. Koch, A. L., Frost, F. and K.C. Trujillo. 2006. Paleontological discoveries at Curecanti National Recreation Area and Black Canyon of the Gunnison National Park, Upper Jurassic Morrison Formation, Colorado. Pages 35-38 in Foster, J. R. and S. G. Lucas, editors. Paleontology and geology of the Upper Jurassic Morrison Formation. New Mexico Museum of Natural History and Science, Albuquerque, NM. Bulletin 36. Articles & ResearchShowing results 1-8 of 8
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Last updated: April 24, 2025
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