The Mill Canyon Dinosaur Tracksite contains a diverse assemblage of fossilized tracks. More than 200 individual tracks have been discovered, including tracks from long-necked herbivorous dinosaurs, several types of carnivorous dinosaurs (including sickle-clawed “raptors”), and crocodiles. This site is one of the largest and most diverse tracksites known from the Early Cretaceous time period in North America.

The interpretive trail is 1/4 mile long and is composed of a series of marked paths and boardwalks that form a loop around the tracksite. From the kiosk, take the marked trail down a hill and through a fence, and continue along the trail. Follow the trail from sign to sign. The tracks are fragile and can be damaged by walking on the track surface. Please stay on the trail at all times!

Approximately 112 million years ago, the tracksite area was a mud flat where a shallow lake was drying up. The mud flat was covered by a 1-foot-thick layer of lime mud, and that lime mud was covered by a mat of algae. The algae formed when the mud flat was still under water. The bumps on the surface of the track layer are petrified colonies of algae.

Slide marks on the track layer show that animals sometimes slid on the soft mud of the flat. A dinosaur coprolite (fossilized dung) with pieces of leaves in it was found on the track layer. From this discovery, we know that land plants grew near the lake. Seed ferns and conifers were common land plants at this time in geologic history. Fossilized tracks and traces show that this area was visited by a diverse array of dinosaurs, reptiles, birds, and mammals.