Bellah was the author of 19 novels, including The Valiant Virginian (the inspiration for the 1961 NBC television series The Americans), and Blood River.

Some of his short stories were turned into films by John Ford, including Fort Apache, She Wore a Yellow Ribbon, and Rio Grande.

With Willis Goldbeck he wrote the screenplays for Sergeant Rutledge (1960) and The Man Who Shot Liberty Valance (1962).

[1][2] In World War I, Bellah enlisted in the Canadian Army, and served as a pilot in the 117th Squadron of Great Britain's Royal Flying Corps.

In the early stages of his career, Elmore Leonard modelled his style closely after Bellah's writing.