What important geological formation is found in western North Dakota?

The Bakken Formation is a significant geological formation located in western North Dakota, recognized for its rich reserves of oil and natural gas. This formation extends into parts of Montana and Canada, but it is most prominently associated with North Dakota due to the state's substantial oil production that has been derived from it in recent years. The discovery and exploitation of the Bakken have transformed the state's economy, creating jobs and attracting attention from energy companies and investors alike.

In contrast, while the Great Plains is a vast region that covers much of North Dakota, it does not denote a specific geological formation like the Bakken does. The Black Hills, located further south mostly in South Dakota, are a distinct mountain range with different geological characteristics and are not found in western North Dakota. The Mississippi River Valley is also unrelated as it pertains to the major river system primarily located to the east of North Dakota and focused on the river's ecosystem rather than a distinctive geological formation tied to oil production. Thus, the Bakken Formation stands out as the crucial geological feature that impacts both the environment and the economy of western North Dakota.