Physiographic provinces, Quaternary faults, Quaternary volcanic rocks, and Quaternary volcanic vents in Utah.
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Comprising essentially the western half of Utah, the Basin and Range Province is separated from the Middle Rocky Mountains province by the Wasatch fault zone, and from the Colorado Plateau province by the Basin and Range-Colorado Plateau transition zone.

Within the Basin and Range and the transition zone, east-west structural extension is thought to have taken place over the past 17 million years creating numerous north-south-oriented, fault-bounded blocks.

Prior to Basin and Range extension (during mid-Cenozoic time), voluminous silicic volcanism with associated hydrothermal activity took place within several east-west trending belts.

Patterns of volcanism changed during the later stages of Basin and Range development to less-voluminous basalt and rhyolite (bimodal assemblage), spatially controlled by north-south Basin-and-Range faults.