Kenneth S. Deffeyes was a geologist who worked with M. King Hubbert, the creator of the Hubbert peak theory, at the Shell Oil Company research laboratory in Houston, Texas. He claimed Chickasaw ancestry. Deffeyes made a lively personal impression. McPhee characterized him in Basin and Range (1981): "Deffeyes is a big man with a tenured waistline. His hair flies behind him like Ludwig van Beethoven. He lectures in sneakers. His voice is syllabic, elocutionary, operatic. ... His surname rhymes with 'the maze.'"