The trade paper Radio & Records said, "Dark's distinctive voice has been heard in more award-winning commercials than any announcer in broadcast history."

He quickly advanced to stations in Cleveland, Miami, New Orleans, St. Louis, finally landing a 1963-66 stint as the evening DJ for KLAC in Los Angeles.

[1] Over the course of his career, Dark was the spokesman for Keebler Cookies, the Chevrolet Camaro, AT&T, Kmart, Texaco, Armor-All, Whitman's Chocolates, Dreyer's Ice Cream, and many other Blue Chip companies.

[citation needed] Dark also provided the "This program is about Unsolved Mysteries..." opening narration for the popular 80s and 90s true crime series.

He also narrated historical documentaries for the Biographical series on History Channel, including Johnny Cash: The Man in Black, and General Robert E. Lee.