Sawatch Uplift

The Sawatch Uplift is a prominent geologic anticline in the Rocky Mountains in central Colorado in the United States. It was formed as a bulge in the North American Plate approximately 70–65 MYA during the Laramide orogeny that created the modern Rocky Mountains. The uplift runs north-south for several hundred miles from central Colorado into northern New Mexico. The Sawatch Range and Mosquito Range 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 a trough between the Sawatch and Mosquito Range that is part of the larger Rio Grande Rift. The trough runs southward from Leadville into the New Mexico. The northern part of the rift forms the headwater valley of the Arkansas River.

References

*"Roadside Geology of Colorado", Halka Chronic (1980).