The Yates oilfield, in southeastern Pecos County, was discovered on October 28, 1926, when the Ira G. Yates 1-A, operated jointly by Mid-Kansas Oil and Gas Company and Transcontinental Oil Company, reached a depth of 992 feet in the San Andres formation and began producing 450 barrels of oil a day. Oil prospecting had started in Pecos County in 1900. In 1923 Transcontinental Oil Company, a corporation owned by Michael Late Benedum and Joseph Clifton Trees, leased drilling acreage on an 8,000-acre tract belonging to Ira G. Yates. On October 5, 1926, Transcontinental Oil Company and Mid-Kansas Oil and Gas Company, a subsidiary of the Ohio Oil Company, jointly spudded the Ira G. Yates 1-A. The well was drilled with cable tools for less than $15,000. The operators of Yates 1-A, which was located in isolated and almost inaccessible country, were faced with the problem of delivering their oil to the buyer. Since Humble Pipe Line Company already had a main line at McCamey, across the river in Upton County, that company contracted to run the Yates 1-A oil and began building a 55,000-barrel steel storage tank. The well was shut in until the storage tank was completed. With production in the Yates 1-A assured, the managements of Mid-Kansas and of Transcontinental moved a rig onto location for a second well on the Yates lease at the end of December 1926. By February 11, 1927, it reached a depth of 1,002 feet and gauged a daily average of 3,440 barrels of oil. By spring 1927 three more wells were completed, for a daily average production of 9,099 barrels of oil. Since the pipeline and adequate storage tanks were not yet completed, the new wells were shut in. However, Mid-Kansas and Transcontinental, which owned all leases near the discovery well, continued to drill at new sites. The field was extended and opened up to other operators on June 17, 1927, when Mid-Kansas and Transcontinental brought in a good producer on land owned by Mrs. M. A. Smith. Also in June 1927 Allsman and Bell Oil Company widened the field a mile to the east when its well, located in the bed of the Pecos River, reached the oil-saturated lime at 1,002 feet. Production in Yates field was pinched back to 7,000 barrels a day because of limited storage and pipeline access. At the end of June the major producers in the field completed their Yates 6-A. High gas pressure in the hole forced an astonishing flow of 500 barrels of oil per hour from a depth of 1,045 feet. The crude broke through the connections in the well and ran out of its pipe onto the ground. Caught in the nearby canyons, the oil was picked up later by pumps. By September 23, 1927, Mid-Kansas and Transcontinental reported twelve producers with pinched daily production of 4,035 barrels. Six other companies claimed one producer each.
Flush production from Yates field presented storage and transportation problems to the operators. On October 1, 1927, the first field-wide proration in Texas went into effect. Allowables were based on the total potential production of all wells in the field. Each well was given a share of the pipeline outlet equal to the ratio of its potential to that of the total field. Shortly thereafter, a rule that limited each well's penetration of the lime formation to 225 feet was adopted to allow each operator the same advantage in the cavernlike reservoir. On June 1, 1928, an official order placed the proration enforcement in Yates field under the direction of the Railroad Commission. On July 1 a new proration program was adopted, based on both potential production and acreage holdings. In October 1928 oil migrating from poorly cased deep wells was discovered seeping under the banks of the Pecos River and floating on the surface. Thousands of barrels of crude were recovered daily by skimming the river and by drilling 20-foot to 400-foot wells. By mid-1933 over 3.25 million barrels of seepage oil had been gathered. Drilling activity in the field peaked at the end of 1928, when 175 producing wells were completed and ten dry holes were plugged. By July 1929 the field consisted of 15,000 proven acres. In September 1929 the Yates 30-A, operated by Transcontinental and Mid-Kansas and located a few hundred yards down the canyon from the discovery well, set a world record when it produced 8,528 barrels of oil per hour or 204,672 barrels per day. Field production peaked in 1929, when more than 41 million barrels of oil was produced. In 1930 Transcontinental sold its interest in Yates field to Mid-Kansas.
By 1941 Yates field production had dropped to under six million barrels of oil, and on August 31, 1943, the Railroad Commission ordered the observance of special rules to reduce water production in the field. Oil production climbed to over thirteen million barrels during 1945 and to more than eighteen million by 1948 from 22,671 proven acres. The number of flowing wells that year was 511, seventy-eight of which were on artificial lift. In 1962 the Ohio Oil Company and its subsidiary, Mid-Kansas Oil and Gas Company, became known as Marathon Oil Company. From November 1968 through December 1972 five operators in the field were permitted by the Railroad Commission to inject salt water and gas into producing formations to maintain field pressure and to store gas temporarily. On July 1, 1976, unitization became a reality in Yates field with Marathon as unit operator. The injection of gas back into the reservoir maintained pressure and retarded water encroachment, thus exposing a greater area of the reservoir to gravity drainage and doubling field production. On January 11, 1985, Yates field produced its billionth barrel of oil. By 1988 new techniques were in use in the field-secondary recovery methods of water-flooding, polymer injection, carbon dioxide flooding, and the sinking of new wells within the proven acreage, or infill drilling. At the end of 1989 Yates field reported a yearly production of 27,292,621 barrels of oil and 56,120,285 million cubic feet of gas. Cumulative crude production of 1,180,073,629 barrels over the first sixty-three years placed Yates among the most prolific oilfields in the world.