4. JOHNELLE HUNT

$4.3 billion

SOURCE: Trucking

AGE: 90 • RESIDENCE: Fayetteville, AR

SELF-MADE SCORE: 7

Hunt rang in her 90th birthday this year at an Arkansas Razorbacks basketball game, where the state’s richest woman was treated to cake and cheers during halftime. The matriarch of J.B. Hunt Transport Services, which she cofounded in 1961 with her late husband, has plenty to celebrate. Strong demand for freight transport pushed revenue up 26% last year, to a record $12.2 billion. She is the largest shareholder, with a 17% stake.