El Dorado and the First Science Oil Strike

On October fifth, nineteen fifteen, a drill bit punched through limestone in Butler County, Kansas, and changed the oil industry forever. The Stapleton Number One well, drilled by a subsidiary of Cities Service Company, hit oil at six hundred feet and began producing ninety-five barrels a day. When drillers deepened it to twenty-five hundred feet, it pumped a hundred and ten barrels from the Wilcox sands below.

But what made El Dorado different from the gusher at Spindletop in Texas fourteen years earlier was how the well was found. In June of nineteen fourteen, the city of El Dorado hired Erasmus Haworth, the retiring State Geologist of Kansas, to map the geology of Butler County. Haworth's fieldwork identified a subsurface feature called the El Dorado Anticline, an arch of rock layers where oil and gas could theoretically accumulate. The drilling followed the science.

It was the first time in history that a major commercial oil field was discovered through systematic geological survey rather than instinct or luck. After El Dorado, no serious oil company would drill a major well without consulting a petroleum geologist first. The field rewrote professional standards for the entire industry.

El Dorado grew from three thousand to more than ten thousand people within three years. The field eventually encompassed thirty-four square miles and produced twenty-nine to thirty-six million barrels per year at its peak, a majority of all Kansas oil output, and roughly nine percent of world oil production. When the United States entered the First World War in nineteen seventeen, El Dorado was already pumping. The fuel that moved American soldiers and machines across France passed partly through this Kansas county.

The Stapleton well site is still marked and open to visitors today.