In the plain rock lands of the Dinosaur Park Formation in Alberta, Canada would lie a migrating herd of Adult Centrosauruses, being a crowd due to there being hundreds of these One-horn Ceratopsians. These ceratopsians would be similar to Styracosaurus, but Centrosaurus lived in a different region away from them. The herd of Centrosaurus would focus on leaving the current land they are in for more vegetation and survival. Main predators such as Gorgosaurus and Daspletosaurus would take on these Ceratopsians, but for now aren't seen. No babies, teenagers and subadults are in the herd because it has not been the aftermath of mating season, nor has mating season started yet.

The large herd of Centrosaurus would be migrating, just recently leaving their nesting grounds. The herd would not know what was to come next, as they would continue migrating to a peaceful land they would know, but the only thing that would increase the fatal lost of most of the members of the herd would be, the river crossing. The river crossing would involve these heavy ceratopsians to be forced to swim, the river is not shallow like the normal ponds, instead whats worse? Crocodiles, such as Deinosuchus would swim around the river, making it difficult for the herd to manage to survive the crossing.