The Great Basin district, during the Paleozoic and lower Mesozoic, was a geosynclinal area, in which 30,000 feet of sediments accumulated. The district was folded in the mid-Mesozoic revolution to form a mighty mountain system. It was thereafter degraded, during the Cretaceous and most of the Tertiary, to a region of low relief.

By Pliocene time the crust in the Pacific geosynclinal belt west of the Great Basin district had become so weakened that the intermediate Sierra Nevada massif began to creep westward under gravity. The Great Basin district followed, its crust was extended, and block-faulting commenced.

In the Pleistocene, western North America was epeirogenically uplifted, and as a result the gravity flow increased. The Sierra Nevada massif and its extensions moved westward as much as 60 miles, shortening the crust in California, and extending the crust in the Great Basin district, to that extent. The Great Basin District then collapsed, ponded its drainage, and occasioned a topographic discrepancy which caused the Grand Canyon of the Colorado to be cut.