Thomas Hezikiah Mix was born January 6, 1880, in Mix Run, Pennsylvania, about north of State College, Pennsylvania, to Edwin Elias Mix and Elizabeth Heistand. He grew up in nearby DuBois, Pennsylvania, where his father, a stable master for a wealthy lumber merchant, taught him to ride and love horses. He spent time working on a local farm owned by John DuBois, a lumber businessman. He had dreams of being in the circus and was rumored to have been caught by his parents practicing knife-throwing tricks against a wall, using his sister as an assistant.