The Sawatch Uplift The place name "Sawatch" is pronounced . This name derives from the

Ute language Ute Givón, T. ''Ute Reference Grammar''. John Benjamins Publishing Company, 2011 is a dialect of the Colorado River Numic language, spoken by the Ute people. Speakers primarily live on three reservations: Uintah-Ouray (or Northern Ute) in nor ...

noun A noun () is a word that generally functions as the name of a specific object or set of objects, such as living creatures, places, actions, qualities, states of existence, or ideas.Example nouns for: * Organism, Living creatures (including people ...

"''sawup''" meaning "sand dunes". The

Spanish language Spanish ( or , Castilian) is a Romance languages, Romance language of the Indo-European language family that evolved from colloquial Latin spoken on the Iberian peninsula. Today, it is a world language, global language with more than 500 millio ...

version of this name is usually spelled "Saguache", while the

English language English is a West Germanic language of the Indo-European language family, with its earliest forms spoken by the inhabitants of early medieval England. It is named after the Angles, one of the ancient Germanic peoples that migrated to t ...

version is usually spelled "Sawatch". is a prominent

geologic Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ear ...

anticline In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the ...

in the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...

in central

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

. It was formed as a bulge in the

North American Plate The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Pacifi ...

approximately 70–65

MYA Mya may refer to: Brands and product names * Mya (program), an intelligent personal assistant created by Motorola * Mya (TV channel), an Italian Television channel * Midwest Young Artists, a comprehensive youth music program Codes * Burmese ...

during the

Laramide orogeny The Laramide orogeny was a time 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 o ...

that created the modern Rocky Mountains. The uplift runs north–south for about in central Colorado. The

Sawatch Range The Sawatch Range or Saguache RangeThe place name "Saguache” is pronounced “Sawatch” . This name derives from the Ute language noun "''sawup''" meaning "sand dunes" and is spelled using the Spanish language version of this name "Saguach ...

and

Mosquito Range The Mosquito Range (elevation approximately 14,000 ft) is a high mountain range in the Rocky Mountains of central Colorado in the United States. The peaks of the range form a ridge running north–south for roughly 40 mi (64 km) fr ...

were both formed as part of the uplift. Approximately 35 MYA, stresses in the continental plate in the center of the uplift caused the center to collapse, forming the upper Arkansas River graben. This is a trough between the Sawatch and Mosquito Range that is part of the larger

Rio Grande Rift The Rio Grande rift is a north-trending continental rift zone. It separates the Colorado Plateau in the west from the interior of the North American craton on the east. The rift extends from central Colorado in the north to the state of Chihu ...

. The trough runs southward from

Leadville, CO The City of Leadville is a statutory city that is the county seat, the most populous community, and the only incorporated municipality in Lake County, Colorado, United States. The city population was 2,602 at the 2010 census and an estimated ...

to the

San Luis basin The San Luis Valley is a region in south-central Colorado with a small portion overlapping into New Mexico. The valley is approximately long and wide, extending from the Continental Divide on the northwest rim into New Mexico on the south. It co ...

. The upper Arkansas Graben forms the headwater valley of the

Arkansas River The Arkansas River is a major tributary of the Mississippi River. It generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's source basin lies in the western United S ...

References

*''Roadside Geology of Colorado'', Halka Chronic (1980). Geologic provinces of Colorado {{US-geology-stub