Located in Yazoo County, Tinsley Field currently produces both crude oil and natural gas. In 1939 Tinsley Field became the first commercially successful oil field discovered in Mississippi. The giant field classification typically requires the production of 100 million standard forty-two-gallon barrels of crude oil. By the end of 1947 Tinsley had already produced in excess of 100.9 million barrels of oil, thus qualifying for giant field status. Its peak yearly production was in 1942, when it produced more than 28 million barrels of oil.
The accumulation of oil and gas at Tinsley resulted from the arching of geological units over a deep subsurface salt structure. Indications of arching were first discovered by F. F. Mellen, a geologist with the Mississippi State Geological Survey, then headquartered at the University of Mississippi. Mellen had been conducting surface geological mapping in Yazoo County and found indications of arching along streams and other surface exposures of clay beds. On 12 April 1939 the Mississippi State Geological Survey issued a press release with its interpretation of the information gathered in the field. Shortly thereafter, Union Producing completed Mississippi’s first commercial oil well, the C. G. Woodruff No. 1 well, at a total depth of 4,560 feet. The well produced from an oil-saturated sand bed that came to be called the Woodruff Sand. The discovery of that oil at Tinsley Field made national news.
By 2007 578 wells had been drilled at Tinsley, with 50 actively producing in the field.
- T. A. Fitzgerald, in Giant Oil and Gas Fields of the Decade, ed. M. T. Halbouty (1980)
- Kenneth K. Landes, Petroleum Geology of the United States (1970)
- F. F. Mellen and T. E. McCutcheon, Mississippi State Geological Survey Bulletin 39 (1940)
- W. H. Moore, Tinsley Field, 1939–1974: A Commemorative Bulletin (1974)