Petroleum discoveries in this county began in 1923, with recovery of oil in the San Andres Formation--eventually penetrated by over 2,000 shallow wells. In late 1948, rigs drilling deeper than 6,000 feet tapped the Canyon Reef Geological Formation. Four exploratory wells--Sun Oil Company's Schattel; Magnolia's Winston; Standard Oil Company of Texas Brown; Lion Oil Company's C. T. McLaughlin--and other extensive drilling defined a gigantic field covering 85,000 acres and containing oil reserves estimated to total at least four billion barrels. The local economy and growth rate improved greatly. Many farmers and ranchers who had fought years of drouth and adversity paid off debts, modernized their homes, and continued to live on their land. On Oct. 8, 1973, twenty-five years after the Canyon Reef discovery, Scurry County produced from that formation its billionth barrel of oil, and in a week of festivities paid tribute to the petroleum industry. The celebrated billionth barrel of oil came from the well near this marker. By 1973, Scurry County was producing 3.2 per cent of all the oil recovered annually in the United States. (1975)