Thocmentony was a member of the Northern Paiute tribe in the United States. She was a writer, lecturer, educator, interpreter, and tribal leader. When she was 16, the Paiute War of 1860 broke out, resulting in the deaths of several of her family members. She took on the role of peacemaker and interpreter after that. In 1872, she accompanied her tribe to a new reservation in Oregon, where she interpreted for the reservation agent. However, she ended this role in 1876 when a new agent took the post, as he was hostile and unyielding to the troubles of her people.

Thocmentony taught Native American children in school and continually advocated for her community. She once gave a lecture in San Francisco that caught the attention of the U.S. president, bringing to light the challenges faced by the Paiutes. However, she is best known for her book Life Among the Paiutes: Their Wrongs and Claims. This book provided an accurate insight into the everyday life of the Paiutes and the negative impact that white settlement had on them. It is considered the first known autobiography written by a Native American woman.