Born in Las Vegas, New Mexico, Clark graduated from New Mexico Highlands University in Las Vegas at age 21, and married Thomas Patrick Clark on August 6, 1919. She gave birth to an only son, Thomas Patrick, Jr., who later died in World War II.

She began her career teaching English at the Highlands University. However, in the early 1920’s, she transferred to a job teaching Native American children for the Tesuque pueblo people, which lasted for 25 years. Clark found that the underfunded Tesuque School couldn’t afford any substantial instructional material. She wrote her own books for the 1st to 4th grade one-room schoolhouse.

Between 1940 and 1951, the United States Bureau of Indian Affairs published 15 of her books, all relating to her experiences with the Native Americans. In 1945, the Institute for Inter-American Affairs sent Clark to live and travel for five years in Mexico, Guatemala, Costa Rica, Ecuador, Peru, and Brazil.Those experiences led her to write books such as Magic Money, Looking-for-Something, and The Secret of the Andes, which won the 1953 Newbery Medal. In the 1940s she also wrote books for the Haskell Foundation and the Haskell Indian Nations University at Lawrence, KS; one of them " The Slim Butte Raccoon" was illustrated by Andrew Standing Soldier.

She also won the Catholic Library Association’s 1963 Regina Medal, and the Bureau of Indian Affairs' 1962 Distinguished Service Award. Clark died in 1995 after writing 31 books which took a glance at Native American culture.