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My Public Lands

Walking with Giants

We follow 167-million-year-old dinosaur tracks in the ancient ocean shores of...Wyoming?

story by Sarah Beckwith, BLM Wyoming

Imagine yourself walking along an ocean shoreline 167 million years ago with dozens of dinosaurs, picking up bites to eat from what washed up on the last high tide.

The ground is soft and your feet sink down in the thick ooze, leaving a clear footprint with every step you take.

These footprints are the tangible remains of the Middle Jurassic population of meat-eating dinosaurs that walked on this ancient tidal flat, and are preserved at the Red Gulch Dinosaur Tracksite in Wyoming. The tracksite is not only a gem among America's public lands, it is also one of the premier dinosaur tracksites in the world.

The limy mud over which the dinosaurs walked probably felt similar to cement just starting to harden. The tracks were perfectly preserved when the ground fossilized and was covered by more layers of ooze and then by fine sand, filling the tracks and preserving their shape. Over the years, layer upon layer of sediment filled in over the top. Much later, erosion went to work and removed those layers, exposing the tracks that were made all those millions of years ago.

Scientists are excited about this site because its size makes it the largest in the state and its age marks it as one of only a few worldwide from the Middle Jurassic Period (160 million to 180 million years old).

The discovery also means that the geologic history of the area needs to be rewritten.

The Giant's Footprints
photo by BLM Wyoming

For part of the Middle Jurassic, Wyoming was covered periodically by an ancient ocean called the Sundance Sea. Until the tracks were found, scientists thought that only sea-dwelling creatures could have lived in the area which would mean there shouldn't be any dinosaur footprints here at all. But there are thousands of tracks in the 40-acre area. The dinosaur tracks were clearly made just at the shoreline, not in deep ocean water, and there must have been large areas of dry land to support not only dinosaurs but other animals and plants.

The Red Gulch Dinosaur Tracksite is one of the most extensively and intensively studied dinosaur tracksites in the world and continues to provide important information about the dinosaurs and paleogeography of western North America during the Middle Jurassic Period. BLM scientists working here have pioneered photogrammetric techniques currently used around the world that allow tracks and other fossils to be digitally documented for research and curation. A podcast was recently made available on YouTube that showcases the site and details some of the state-of-the-art photogrammetric work done on dinosaur footprints in northern Wyoming.

More than 12,000 people from 11 countries and more than 30 states visited the Red Gulch Dinosaur Tracksite in 2013. In addition to finding hundreds of dinosaur tracks, visitors are also enjoying the recreational area's recent facelift which includes a new shade shelter, the Trex boardwalk, and well-maintained picnic area and interpretive signage. The Red Gulch Dinosaur Tracksite exemplifies Wyoming's tremendously rich fossil heritage and provides a unique opportunity for the public to experience one of the world's unique dinosaur tracksites.

Make tracks to see more dinos online!