Whiting Petroleum Corporation is an independent oil and gas company. The Company is engaged in development, production, acquisition and exploration activities primarily in the Rocky Mountains region of the United States. It is engaged in the exploration and production of crude oil, natural gas liquid (NGLs) and natural gas. Its Northern Rocky Mountains operations included properties in the Williston Basin of North Dakota and Montana targeting the Bakken and Three Forks formations and encompassing approximately 736,000 gross developed and undeveloped acres, as of December 31, 2016. Its Central Rocky Mountains operations included properties at its Redtail field in the Denver Julesburg Basin in Weld County, Colorado targeting the Niobrara and Codell/Fort Hays formations and encompassing approximately 157,200 gross developed and undeveloped acres, as of December 31, 2016. Its other operations primarily relate to non-core assets in Colorado, Mississippi, North Dakota, Texas and Wyoming.