Mr. Collins: Most of the oil found in Texas formed from the remains of tiny living things, mostly plankton and algae, that lived in ancient seas millions of years ago. When they died, they sank and were buried under layers of mud and sand.

Mr. Collins: Over millions of years, those layers piled higher and higher. The heat and pressure deep underground slowly changed the remains into oil and natural gas. Because oil is lighter than water, it moved upward through the rock until it was trapped under a layer that it could not pass through.

Mr. Collins: That's where drillers find it. In 1901, a well at Spindletop, near Beaumont, struck one of these traps, and oil shot high into the air. That discovery helped turn Texas into a major oil producer.