Geraldine Bonner was born on Staten Island, New York. Her father, John Bonner, was a journalist and historical writer. As a child, the family moved to Colorado and she lived in mining camps. After moving to San Francisco, California, she worked at a newspaper, the Argonaut, in 1887, and subsequently, she wrote the novel Hard Pan (1900) and used the name "Hard Pan" as a pseudonym. Bonner also wrote short stories which were published in Collier's Weekly, Harper's Weekly, Harper's Monthly, and Lippincott's.