Roosevelt was born as Kenneth Stanhope Sanderson in Meeker in Rio Blanco County in northwestern Colorado.

Throughout the 1940s he both appeared in or performed stunts in 32 films, most notably alongside Randolph Scott and Lloyd Bridges in Abilene Town.

[2] In the 1950s, he appeared in sixty-five episodes as an unnamed townsman on the ABC/Desilu television series, The Life and Legend of Wyatt Earp.

He retired after 1962 with his last appearance being uncredited in the John Wayne and James Stewart film The Man Who Shot Liberty Valance.

He returned home to Meeker, Colorado, where he was living at the time of his death on October 6, 1973, at the age of seventy-five.