Often collaborated with John Clifford.
Directed over 400 educational, industrial and documentary films made by Centron Productions in Lawrence, Kansas. His real first name was Harold, but he used his nickname "Herk" on all of his work.
Received a lifetime achievement award from a film institute in Kansas in 1989.
Conceived the plot of Carnival of Souls (1962) after seeing the abandoned Saltaire pavilion / amusement park located in Utah, and coincidentally the site became the setting for the film itself.
Interviewed in Tom Weaver's "Science Fiction Stars and Horror Heroes" (McFarland & Co., 2006).