At first, Erika Bolstad knew only one thing about her great-grandmother, Anna: she was a homesteader on the North Dakota prairies in the early 1900s before her husband committed her to an asylum under mysterious circumstances. As Erika's mother was dying, she revealed more: their family still owned the mineral rights to Anna's land—and oil companies were interested in the black gold beneath the prairies. Their family, Erika learned, could get rich thanks to the legacy of a woman nearly lost to history.

Anna left no letters or journals, and very few photographs of her had survived. But Erika was drawn to the young woman who never walked free of the asylum that imprisoned her. As a journalist well versed in the effects of fossil fuels on climate change, Erika felt the dissonance of what she knew and the barely acknowledged whisper that had followed her family across the Great Plains for generations: we could be rich. Desperate to learn more about her great-grandmother and the oil industry that changed the face of the American West forever, Erika set out for North Dakota to unearth what she could of the past. What she discovers is a land of boom-and-bust cycles and families trying their best to eke out a living in an unforgiving landscape, bringing to life the ever-present American question: What does it mean to be rich?