[8] In 1969, he worked with Dennis Hopper and Peter Fonda in Easy Rider, with his "Hitchhiker" character (credited as "Stranger on Highway") achieving worlwide popularity and also making Askew a recognizable face in subsequent films.

[7] Askew starred for the first time in a role in the almost-forgotten Spaghetti Western Night of the Serpent (1969), which is now considered a cult film.

He continued to work as an actor after that, predominantly appearing in supporting or villain roles in genre films like The Warrior and the Sorceress (1984) and Dune Warriors (1991), as well as guest roles on television series; this includes work on such series as: Bonanza, The High Chaparral, Mission: Impossible, Cannon, The Rockford Files, Quincy, M.E., The Six Million Dollar Man, T. J. Hooker, L.A. Law, MacGyver, Walker, Texas Ranger, Murder She Wrote, and HBO's Big Love.

Askew sang Muddy Waters, Howlin' Wolf and Jimmy Reed songs at The Gaslight Cafe.

According to Bob Dylan, when Luke sang at The Gaslight Cafe it was like a "guy who sounded like Bobby Blue Bland".