Robert Indiana kept a series of illustrated journals during the late 1950s and 1960s, in which he discusses the development of his work as well as his daily life on Coenties Slip.

Indiana's journal entry for March 1, 1961, consists of two pages. In the second page, which includes a color sketch of The Triumph of Tira, the artist explains that he extended the color impact of the work by adding Mars red to the formerly black, dark yellow, and white painting. A comment above the painting, added at a later date, indicates that the work is in the collection of the Sheldon Memorial Art Gallery in Lincoln, Nebraska.