Andra Rush was modest as a teenager, the sort who seemed more likely to be taking orders than giving them when she grew up. She was a middle-class kid from Michigan, and after high school she got a nursing degree and landed a job at a local hospital.

But she felt the nurses were treated unfairly and that the hospital was run irrationally, and a feistiness began to emerge. Likewise an itch to be in charge. She looked at the hospital organizational chart and decided that the only sure way to gain real authority was to be a CEO.

Determined to learn how to run a business the right way, Rush enrolled in M.B.A. classes at the University of Michigan. At the same time, she interned at a trucking company and worked long nursing shifts on weekends. In 1984, she recalls, the emphasis was on getting a good job in corporate America, not on starting a business, but Rush liked the idea of being her own boss. Luckily for her, the trucking industry was being deregulated, and for the first time, entrepreneurs could afford to enter the business. She dropped school and jumped at the chance.

Today, Rush Trucking, based in the Detroit suburb of Wayne, makes 1,400 shipments daily with 1,000 trucks. It generated $132 million in revenue last year, thanks to major customers like General Motors and Ford. Rush, who's part Mohawk, now serves as a mentor for her fellow entrepreneurs and sits on the board of the Native American Business Alliance. More than half of her 350 full-time employees are minorities, and half are women. "She's made a lot of sacrifices to succeed," says Diane Freeman, who's in charge of GM's supplier diversity program. "She's a risk taker."

Rush has never been afraid to take chances. She started out with just three trucks (one new and two used), which she bought with her savings and a little help from her parents. She had maxed out her credit cards and couldn't afford a cell phone, so she forwarded calls to her grandmother's house while she was out drumming up sales. When she was home, she pretended to transfer customers to different lines and used phony voices to make the company seem bigger. She even learned how to repair the trucks herself. In those days, Rush specialized in emergency shipping. She made an impression by accepting every job, even if that meant getting up at 3 a.m. to deliver a shipment herself.

Rush will tell you that the only true pioneer in her family is her paternal great-grandfather, who moved from a Canadian reservation to Detroit, where he helped build many of the city's skyscrapers. She's being modest again.--Nadine Heintz

Nadine Heintz is a staff writer.