Geology
The tracksite is in a limestone layer in the lower part of the Sundance Formation. Its discovery was somewhat surprising, since the Sundance was historically considered to be marine in nature. Indeed, the layer just above the tracksite contains abundant marine fossils including numerous Gryphaea nebrascensis, indicating that later in the Jurassic it was once again submerged.
Read more about this topic: Red Gulch Dinosaur Tracksite