This is my representation of a bayou in the Hell Creek region of western North America between 68 and 66 million years ago, near the end of the Late Cretaceous Period. This region straddles what are now states of Montana, Wyoming, and North and South Dakota, but back then had a humid and semitropical climate more similar to modern Florida or Louisiana. Among the animals you can see in this illustration are the ceratopsian Triceratops prorsus, the tyrannosaurid Tyrannosaurus rex, a pterosaur related to Quetzalcoatlus northropi, and the eusuchian crocodyliform Borealsuchus sternbergii.