The Permian Basin is one of the two richest oil fields in the world. Discovery began in 1920 at a Mitchell County well, followed by the 1923 Big Lake strike, the 1925 boom in Upton County, and then production in Andrews, Crane, Ector, Martin, Midland, Pecos, Ward, Winkler, and 24 other counties. In some years new wells averaged 38 a week. Fortunes were made, lost, and regained within months. Yields were so great that oil brought 50 cents a barrel while drillers paid $5.00 a barrel for drinking water. The area covers 88,610 square miles, centered at Odessa, and extends across a deeply buried prehistoric sea that more than 250 million years ago contained much fish and reptile life, including dinosaurs. Shores and islands later grew giant vegetation until earth changes buried animals and plants in pockets that turned hydrocarbons into petroleum. Within 40 years of its discovery, the Permian Basin was producing 53% of Texas oil and 20% of U.S. crude oil. It also became one of the world's largest producers of channel carbon black, with other by-products including sulphur, asphalt, synthetic rubber ingredients, and petrochemicals.