Born in East Grand Forks, Minnesota, she went for one year to the University of North Dakota across the state line in Grand Forks, North Dakota; she apparently stood out there for her skills at basketball. She was also a fine rider of horses and good with a rifle and a pistol. By her own account, she appeared in Buffalo Bill Cody's Wild West Show, although her biographer John A. Harrison was unable to verify that. In any event, it is clear that she was both a rodeo rider (in male disguise) and later a reporter.
In 1910 she met Samuel Hill, a prominent entrepreneur 33 years her senior, who was by then almost entirely estranged from his wife, although they never divorced. She moved to Portland, Oregon, in 1920 to be near him, and in 1928 he bought her 35 acres (140,000 m2) on the Columbia River and built her a 22-room house, to which she added an elaborate garden. That same year, she bore him a son. An arranged marriage to Hill's cousin Edgar Hill allowed the son, Sam B. Hill, to be raised as legitimate. The house was eventually lost to the construction of the Bonneville Dam.
In her 20s and 30s she had a career as a reporter for various newspapers around the United States, including becoming, in San Francisco, the first female crime reporter in the country. Some time before 1926 she swam the Strait of Juan de Fuca, an achievement possibly exceeding Gertrude Ederle's famed 1926 feat of swimming the English Channel.
Hill was clearly the love of her life, although she had two brief marriages, one to a dentist and one to a doctor. Hill had other lovers besides Bell and, indeed, had two other children besides Sam B. outside his marriage, each by a different woman.
In 1933, the U.S. government decided to obtain Bell's land for the Bonneville Dam project. They offered her US$25,000. She went to court and in 1935 received $78,661, ($72,500 plus interest). After a two year round-the-world voyage including six months in Africa, she moved back to Minnesota, where she raised her son, then in 1953 to Riverside, California. In both places, she was known for her elaborate gardens.
- John Terry, Mona Bell won entrepreneur, beat government, stood tall on her own, OregonLive.com, 2010-01-31, retrieved 2010-08-04.
- Tuhy 1983, pp. 286–289.
- Tuhy 1983, passim., p. 86 for Hill's failure to seek divorce.
- Tuhy 1983, pp. 282–286.
- Tuhy, John E. (1983), Sam Hill: The Prince of Castle Nowhere, Portland, Oregon: Timber Press, ISBN 0-917304-77-2
- John A. Harrison, A Woman Alone: Mona Bell, Sam Hill and the Mansion on Bonneville Rock (2009), Frank Amato Publications, ISBN 1-57188-452-1.