Clarno Formation

thumb|left|Restoration of Haplohippus (middle right) and other animals of the Hancock Mammal Quarry Haplohippus is an extinct genus of the modern horse family Equidae, that lived in the Eocene, from 42 to 38 million years ago. Fossil remains of Haplohippus have been found in the Clarno Formation, part of the John Day Fossil Beds National Monument of the Northwestern United States. While Haplohippus is quite similar to Orohippus, it is considered more primitive in character than Epihippus.

Hemipsalodon ("half-scissor tooth") is an extinct genus of hyainailourid hyaenodonts from the subfamily Hyainailourinae that lived in North America during the middle to late Eocene. H. grandis was the largest hyaenodont found in North America, weighing .

mountain range in Oregon, US

species of plant

Achaenodon is an extinct artiodactyl mammal belonging to the family Helohyidae. It lived in the mid-late Eocene (about 43-39 million years ago) and its fossil remains have been found in North America.