- Permian Basin: Located primarily in Texas and New Mexico, the Permian Basin is the largest and most productive oil and gas field in the United States.
- Eagle Ford Shale: Situated in South Texas, the Eagle Ford Shale is known for its substantial production of oil and natural gas.
- Bakken Formation: Located in North Dakota, Montana, and Saskatchewan (Canada), the Bakken Formation is a significant shale oil-producing region.
- Marcellus Shale: Primarily spanning Pennsylvania, West Virginia, and Ohio, the Marcellus Shale is one of the largest natural gas-producing shale formations in the United States.
- Haynesville Shale: Situated in Louisiana, Texas, and Arkansas, the Haynesville Shale is a prominent shale gas-producing formation.
- Utica Shale: Found beneath the Marcellus Shale, the Utica Shale extends across Ohio, Pennsylvania, and West Virginia and produces both oil and natural gas.
- Niobrara Formation: Spanning Colorado, Wyoming, Kansas, and Nebraska, the Niobrara Formation is known for its oil and natural gas production.
- Barnett Shale: Located in North Texas, the Barnett Shale is one of the earliest shale gas-producing formations in the United States.
- Anadarko Basin: Spread across Oklahoma and parts of Texas, Kansas, and Colorado, the Anadarko Basin is a prolific oil and gas-producing region.
- Haynesville/Bossier Shale: Overlapping Louisiana, Texas, and Arkansas, the Haynesville/Bossier Shale formation is rich in natural gas resources.
- Powder River Basin: Found in Wyoming and Montana, the Powder River Basin is known for its coal bed methane production and also produces conventional oil and gas.
- DJ Basin (Wattenberg Field): Situated in Colorado, the DJ Basin, particularly the Wattenberg Field, is an important oil and gas-producing region.
These are just a few of the major oil and gas-producing formations in the United States. There are additional formations and fields across various states that contribute to the country’s overall production.