- Bakken Formation: This formation is the primary source of oil in North Dakota. It is estimated to hold approximately 2.5 billion barrels of recoverable oil.
- Three Forks Formation: This formation is located beneath the Bakken Formation and is estimated to hold approximately 500 million barrels of recoverable oil.
- Madison Group: This formation is located beneath the Three Forks Formation and is estimated to hold approximately 200 million barrels of recoverable oil.
Oil findings in South Dakota:
- Williston Basin: A small portion of the Williston Basin extends into South Dakota. This basin is the same geological formation that holds the large oil reserves in North Dakota. However, the oil findings in South Dakota are relatively small compared to North Dakota.
- Turner Sandstone: This formation is located in eastern South Dakota and is estimated to hold approximately 100 million barrels of recoverable oil.
- Red River Formation: This formation is located in northeastern South Dakota and is estimated to hold approximately 50 million barrels of recoverable oil.
While there have been significant oil findings in North Dakota and South Dakota, it's important to note that these are just estimates and the actual amount of recoverable oil may vary. Furthermore, the development and production of oil from these formations can be influenced by various factors such as geology, economics, technology, and environmental considerations.