The Lance (Creek) Formation is a division of Late Cretaceous (dating to about 69–66 Ma) rocks in the western United States.

Named after Lance Creek, Wyoming, the microvertebrate fossils and dinosaurs represent important components of the latest Mesozoic vertebrate faunas.

The Lance Formation was laid down by streams, on a coastal plain along the edge of the Western Interior Seaway.

At least tens of thousands of Late Cretaceous vertebrate remains have been recovered from the Lance Formation.

Fossils ranging from microscopic elements to extensive bonebeds, with nearly complete, sometimes articulated dinosaur skeletons, have been found.

[4] "Unnamed ornithurine F"[4] Indeterminate Originally thought to belong to "Cimolopteryx" maxima, but probably a new species.

Also found in the Denver, Ferris, Frenchman, Javelina, Livingston, McRae, North Horn, Scollard, and Willow Creek Formations.

Synonyms with type specimens from this formation include Dynamosaurus imperiosus and Manospondylus gigas.

A dubious ceratopsid probably synonymous with Triceratops horridus Leptoceratops L. gracilis Nedoceratops N. hatcheri "[One] skull,"[28] type specimen.

Triceratops T. horridus "Partial skull and skeleton,"[28] type specimen Indeterminate lambeosaurinae fossils have been found in the Lance Formation.

[31] Edmontosaurus E. annectens Skull, skeletons, including the type specimen, "mummy", and a bone bed.

Thespesius T. occidentalis Teeth, vertebrae, toe bone (including type specimen) A dubious hadrosaurid possibly synonymous with E. annectens "Trachodon" "T." longiceps One partial jaw (YPM 616), type specimen A dubious hadrosaurid possibly synonymous with E. annectens Other land vertebrates include pterosaurs (e.g. cf.