High school diploma
Oil and gas
Harold Hamm grew up milking cows, gathering eggs, and feeding chickens. The youngest of 13 kids born to sharecropper parents in Oklahoma, Hamm says that he hardly remembers a time when he wasn't working. "We came up working for the family unit," Hamm says. "You certainly learned quickly to do your part." At the age of 20, he bought a water pump truck to deliver drilling fluids and service drilling rigs. "That is the company that became Continental Resources (CLR
)," Hamm says. "It was a very meager start." He says he raised his kids in much the same way he grew up. As his fledging company got off the ground, Hamm's wife kept the books and his daughter, starting as young as six, would answer telephones. At the end of last year, the Enid (Okla.)-based company estimated its proved reserves at 257.3 million barrels of oil, with interests in 2,317 wells. Continental Resources generated $627.7 million in revenue, according to the company's 10-K. Hamm remains at the helm. As he puts it: "I get as much excitement going to work today as I did when I was 20 years old."