U.S. shale oil refers to crude oil extracted from shale rock formations using advanced drilling techniques, such as hydraulic fracturing and horizontal drilling. This method has significantly increased oil production in the United States, making it one of the world's leading oil producers. The most notable shale formations include the Permian Basin in Texas and the Bakken Formation in North Dakota. The rise of U.S. shale oil has transformed the energy landscape, contributing to lower oil prices and reducing dependence on foreign oil. It has also sparked discussions about environmental impacts, including concerns over water usage and potential contamination from drilling activities.