""Those old cows knew trouble was coming before we did."" So begins the story of Lily Casey Smith, in Jeannette Walls's magnificent, true-life novel based on her no-nonsense, resourceful, hard working, and spectacularly compelling grandmother. By age six, Lily was helping her father break horses. At fifteen, she left home to teach in a frontier town -- riding five hundred miles on her pony, all alone, to get to her job. She learned to drive a car ("I loved cars even more than I loved horses. They didn't need to be fed if they weren't working, and they didn't leave big piles of manure all over the place") and fly a plane, and, with her husband, ran a vast ranch in Arizona. She raised two children, one of whom is Jeannette's memorable mother, Rosemary Smith Walls, unforgettably portrayed in "The Glass Castle."

Lily survived tornadoes, droughts, floods, the Great Depression, and the most heartbreaking personal tragedy. She bristled at prejudice of all kinds -- against women, Native Americans, and anyone else who didn't fit the mold. "Half Broke Horses" is Laura Ingalls Wilder for adults, as riveting and dramatic as Isak Dinesen's "Out of Africa" or Beryl Markham's "West with the Night." It will transfix readers everywhere.