In the process of teaching the children about literature, she incorporated their voices and stories to write In My Mother's House, and other 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 Tesuque pueblo people.
[3] 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.
[4] Those experiences led her to write books such as Magic Money, Looking-for-Something, and Secret of the Andes, which won the 1953 Newbery Medal.
She also won the Catholic Library Association's 1963 Regina Medal, and the Bureau of Indian Affairs' 1962 Distinguished Service Award.