In her riveting memoir about her hardscrabble childhood, The Glass Castle (2005), Jeannette Walls described being severely burned while boiling hot dogs when she was three years old.

"I used to think being burned was my earliest memory," Walls says during a call to the home she shares with her husband, writer John Taylor, in Culpepper, Virginia. "But I also remember going to a cafeteria with [my grandmother] Lily and her standing up, pointing to me, and shouting to the entire place: SHE'S ONLY TWO YEARS OLD AND SHE'S DRINKING FROM A STRAW! SHE'S A GENIUS!"

The loud, irrepressible and ever-resourceful Lily Casey Smith, who in later years took pleasure in brandishing both her "choppers" and her pearl-handled pistol in the air, is the subject of Wall's captivating new "true-life novel," Half Broke Horses.

Lily grew up in the vast, still-unpopulated reaches of the Southwest. As a child she helped her rancher father break horses. In her teens, she left home to become an itinerant schoolteacher, riding 500 miles to her first job on horseback. She later lived for a while in Chicago, where she worked as a housekeeper for a wealthy family and was seduced and wedded by a bigamist. Chastened, she returned to the Southwest and married Big Jim Smith, and together they managed a spacious ranch in Arizona. Hers is a story that evokes an American way of life that no longer exists. Lily died when Walls was only eight but her she left an indelible imprint on her granddaughter.

"She was a leathery woman and she would just pick you up and toss you in the air. She'd always yell. She'd enter a room and say HERE I AM! She loved to dance. Every time we'd go someplace where there was music, she'd just grab some guy from his seat and start dancing with him. She was always driving us around in this great big station wagon. She thought she was a brilliant driver but she was really quite reckless. There were always cars sort of crashing and screeching around us. But for all her sort of wild recklessness, she was very orderly," Walls remembers.

"She had all these rules and was very bossy. My mother and she would clash very badly. My father and she would clash even worse. When I was growing up, my mother told me on a regular basis that I was just like her mother, and I don't think she meant that as a compliment. Lily glommed onto me at an early age. She sensed a kindred spirit. She was a lot tougher and ballsier than I ever was, but I do think we're similar in a lot of ways."

Among the obvious similarities are Walls' own loud, embracing laughter, a gift for storytelling and the sort of indomitable spirit that enabled Walls to overcome the dysfunctional childhood she describes in The Glass Castle.

These similarities explain why Walls found it so easy to slip into Lily's unusual voice in Half Broke Horses. "I remember Lily so vividly," Walls says.  "I found it was much easier when I wrote in her voice than when I wrote in third person trying to capture her voice. When I was writing in the third person about Lily, I was just writing in my own voice." As she explains in an author's note in the book, Walls' decision to tell this story in her grandmother's distinctive voice rather than as an objective historian is one of the reasons she decided to call her book a "true-life novel."

"I'll bet most people in America have similar ancestors," Walls says. "The details might be different but the overall story is the same—some tough old broad or tough old coot who came to this country and did what had to be done to survive. I think most people are tougher than we realize and that we have this inner strength and resilience that we're not aware of. One of the ways to get in touch with that is to look at our ancestors."

But for Walls, writing Half Broke Horses was also as least as much about gaining an understanding of her own difficult, free-spirited mother, Rose Mary Smith Walls, as getting in touch with her ancestors. "When I was on book tour," she remembers, "readers of The Glass Castle would often ask me why, with a college education, my mother would choose the life she did. At the time I didn't know the answer. But writing about your parents and your ancestors is like going into intensive therapy. You really get at the roots. I now see that the time when she was growing up on the ranch without electricity and running water was the idyllic time of my mother's life. She's always tried to recreate it, the wildness and lack of discipline. Her life is very much a search for that freedom she had as a child."

Now at age 75, Rose Mary is living in a mobile home a hundred yards away from her daughter and son-in-law, surrounded by the menagerie of rescued dogs, feral cats and horses her daughter and son-in-law have collected since abandoning a tony life in New York City for a semi-rural one in northern Virginia. Rose Mary's vivid stories of her childhood and about her parents' lives in the Southwest 50-some years ago helped define her daughter's new book.

In fact, Walls interviewed her mother extensively for Half Broke Horses. She says with deep satisfaction, "My mom gave me these stories without reservations." And, she adds, "She is not a normal mom, whatever the heck that means. But she's a fascinating woman and she's given me a great deal of joy."

Among the most moving stories Rose Mary shared "so passionately and tenderly" with her daughter was the story of half-broke horses, the wild horses captured on the range that were only half broken by her father's ranch hands. "Hearing her describe their plight and the love and affinity she had with these creatures that don't belong anywhere really struck me," Walls says. "Mom really does see herself that way, as a creature who is a little too wild for civilization but broke enough, civilized enough, that she can't survive in the wild."

Reflecting on the experiences of her grandmother and mother, Walls says, "It's a bit of an anachronism, but there's a lot to be said for the tough pioneer spirit and the untamed wilderness. I think it's important that we don't forget our roots. And our own half-brokeness."

Half Broke Horses is Walls' evocation of that American legacy.

Alden Mudge writes from Berkley, California.

No one familiar with Walls's affecting memoir, The Glass Castle, will be surprised by her subtitle here: Walls is a careful observer who can give true-life stories the rush and immediacy of the best fiction. Here she novelizes the life of her grandmother, giving herself just the latitude she needs to create a great story. Lily Casey Smith is one astonishing woman, tough enough to trot her pony across several hundred miles of desert to her first job when she's only a teenager. After a brief stint in Chicago and marriage to a flim-flam man, she's back in the West, teaching again and eventually remarrying, helping her fine new husband at the gas station, raising her children, and running hootch if she must to make ends meet during the Depression. Her story is at once simple and utterly remarkable, for this is one remarkable woman-a half-broke horse herself who's clearly passed on her best traits to her granddaughter. VERDICT Told in a natural, offhand voice that is utterly enthralling, this is essential reading for anyone who loves good fiction-or any work about the American West. [See Prepub Alert, LJ 6/1/09.]-Barbara Hoffert, Library Journal

For the first 10 years of her life, Lily Casey Smith, the narrator of this "true-life novel" by her granddaughter, Walls, lived in a dirt dugout in west Texas. Walls, whose megaselling memoir, The Glass Castle, recalled her own upbringing, writes in what she recalls as Lily's plainspoken voice, whose recital provides plenty of drama and suspense as she ricochets from one challenge to another. Having been educated in fits and starts because of her parents' penury, Lily becomes a teacher at age 15 in a remote frontier town she reaches after a solo 28-day ride. Marriage to a bigamist almost saps her spirit, but later she weds a rancher with whom she shares two children and a strain of plucky resilience. (They sell bootleg liquor during Prohibition, hiding the bottles under a baby's crib.) Lily is a spirited heroine, fiercely outspoken against hypocrisy and prejudice, a rodeo rider and fearless breaker of horses, and a ruthless poker player. Assailed by flash floods, tornados and droughts, Lily never gets far from hardscrabble drudgery in several states—New Mexico, Arizona, Illinois—but hers is one of those heartwarming stories about indomitable women that will always find an audience. (Oct.)