The Dakota Hogback is a long hogback

Hogback (geology)

A hogback is a homoclinal ridge, formed from a monocline, composed of steeply tilted strata of rock protruding from the surrounding area. The name comes from the ridge resembling the high, knobby spine between the shoulders of a hog. In most cases, the two strata that compose a hogback are...

 ridge at the eastern fringe of the Rocky Mountains

Rocky Mountains

The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...

 that extends north-south from southern Wyoming

Wyoming

Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...

 through Colorado

Colorado

Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

 and into northern New Mexico

New Mexico

New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

 in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. The ridge is prominently visible as the first line of foothills along the edge of the Great Plains

Great Plains

The Great Plains are a broad expanse of flat land, much of it covered in prairie, steppe and grassland, which lies west of the Mississippi River and east of the Rocky Mountains in the United States and Canada. This area covers parts of the U.S...

. It is generally faulted along its western side, and varies in height, with gaps in numerous locations where rivers exit the mountains. The ridge takes its name from the Dakota Formation

Dakota Formation

The Dakota Formation is a geologic formation composed of sedimentary rocks deposited on the western side of the Late Cretaceous Western Interior Seaway. F.B. Meek and F.V. Hayden named it for exposures along the Missouri River near Dakota City, Nebraska...

, a sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

 formation that underlies the ridge. The hogback was formed during the Laramide orogeny

Laramide orogeny

The Laramide orogeny was a period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the orogeny are in dispute, as is the cause. The Laramide...

, approximately 30 million years (30 my) ago, when the modern Rockies were created. The general uplift to the west created long faulting in the North American Plate

North American Plate

The North American Plate is a tectonic plate covering most of North America, Greenland, Cuba, Bahamas, and parts of Siberia, Japan and Iceland. It extends eastward to the Mid-Atlantic Ridge and westward to the Chersky Range in eastern Siberia. The plate includes both continental and oceanic crust...

, resulting in the creation of the hogback.

While the hogback was created during the Laramide Orogeny, the geologic strata comprising the hogback are much older. For example, fossilized data such as dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

 footprints have been observed in the exposed strata, created by dinosaurs which lived during the Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 Period approximately 150 my ago. Some of these footprints were attributed to the Diplodocus

Diplodocus

Diplodocus , or )is a genus of diplodocid sauropod dinosaur whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a Neo-Latin term derived from Greek "double" and "beam", in reference to its double-beamed chevron bones...

 dinosaur and could be seen on the hogback west of Denver, Colorado

Denver, Colorado

The City and County of Denver is the capital and the most populous city of the U.S. state of Colorado. Denver is a consolidated city-county, located in the South Platte River Valley on the western edge of the High Plains just east of the Front Range of the Rocky Mountains...

as recently as the 1980s.