As the series continued on the air, episodes began to focus on nearly any portion of the American West, not just the Death Valley country.

Reagan appeared in 21 episodes of Death Valley Days, including the 1965 segment "A City Is Born" in which he played mining developer Charles Poston, the "Father of Arizona".

[3] Like Reagan, Taylor appeared as a character in some of the shows, including "The Day All Marriages Were Cancelled" (1966), also based on the career of Charles Poston.

[10] Taylor became gravely ill in 1969, and after 69 episodes was succeeded by Dale Robertson, former star of two other Western series, Tales of Wells Fargo and Iron Horse.

In 1975, the show briefly returned in reruns, with singer Merle Haggard providing narration for some previously produced episodes.

Some, (such as Don Haggerty, John Pickard, Gregg Barton, Michael Vallon, James Seay, Guy Wilkerson and Roy Engel) appeared in multiple episodes over the entire run of the series.

Working with their New York advertising agency, McCann-Erickson, they settled on creating a radio program to highlight Death Valley, the obscure location of much of the company's borax mining operations.

As a long-time New Yorker, Woodman had never been to Death Valley and the initial story of the discovery of borax was written entirely from reference books.

[6]: 79  Originally, McCann was interested in one minute advertising spots on television, but found so few available that full program sponsorship was more feasible.

[2]: 48  The series required historical accuracy for its stories, breaking out of the standard Western genre plotlines, instead focusing on actual pioneer events.

[12] Filming would take place approximately six times per year, and while on location, the cast and crew would stay at the Pacific Coast Borax Company's Death Valley resort, the Furnace Creek Inn.

At the time, the conventional approach was exactly the opposite - national release on a weekly schedule in order to achieve a consistent audience.

However, McCann-Erickson felt that the previous popularity of the radio program would overcome those obstacles, a theory that was proven in their first season of high Nielsen ratings.

To make it easier for viewers to distinguish between old and new, some blocks of syndicated Death Valley Days episodes were shown under other series names and with different hosts.

This was common practice at the time among syndicated series because it was easy to reshoot the hosting portions of an episode without affecting the main content.

They also noted an increase in visitors to the Furnace Creek Inn, a Death Valley resort owned by show sponsor Pacific Coast Borax.