Mustang Meadows Ranch

Their high-pitched whinnies roll across the plains like a tumbleweed- scatteri ng wind. At dusk one of them rears and paws the air, casting a silhouette that is the very image of freedom. These are mustangs, the legendary wild horses of the American West. Two decades ago, mustangs were headed for extinction. Now, at Mustang Meadows Ranch, a 32,000-acre spread near St. Francis, S. Dak., 1,500 of them have found sanctuary and a managed independence that may help assure their survival.

Descended from horses that escaped from Spanish herds, millions of mustangs roamed the prairie at the start of the 19th...