Operating primarily in Wyoming Territory (1868–1890), cousins Hannibal Heyes and Jedediah "Kid" Curry (whose boyish face spawned the nickname) are the two most successful outlaws in the history of the West.

However, crime-fighting methods are evolving to foil them; safes are becoming harder to crack, trains more difficult to stop, and posses more adept at tracking them down.

Through an old acquaintance, Sheriff Lom Trevors (James Drury in the pilot, alternately Mike Road and John Russell in the series), they contact the governor, who is unsure of how voters will react if he extends leniency to Heyes and Curry.

He ultimately strikes a deal to grant them amnesty for their past crimes, with the stipulations that they must not discuss the agreement with anyone and that they will officially still be wanted men until such time as the governor decides that they deserve full clemency.

Starting with "The Man Who Broke the Bank at Red Gap" (season two, episode 16), a slightly revamped introduction partially explained why the renowned duo did not split to evade capture—they were cousins.

Recurring characters include: In the early morning hours of December 31, 1971, series star Pete Duel died of a self-inflicted gunshot wound at the age of 31.

Upon learning of Duel's death, executive producer Jo Swerling Jr. initially wanted to end the series, but ABC refused.

The entire company was reassembled and back in production by one o'clock that day shooting scenes that did not involve Peter — only 12 hours after his death.

[1]: 28 Series writer, director, and producer Roy Huggins contacted actor Roger Davis (who provided narration for the series, and who had also appeared in episode 19 "Smiler with a Gun") the day of Duel's death to fill the role of Hannibal Heyes, and actor/voice man Paul Frees came in to loop Duel's unfinished ADR on "The Men That Corrupted Hadleyburg".

[2] Davis was fitted for costumes the following day, and began reshooting scenes Duel had previously completed for an unfinished episode the following Monday.

[1]: 29–30 Alias Smith and Jones began with a made-for-TV movie of the previous year called The Young Country about con artists in the Old West.

Roger Davis starred as Stephen Foster Moody, and Pete Duel had the secondary but significant role of Honest John Smith.

This, as well as the fact that the long-prominent Western genre was giving way to police dramas, brought the show to an end on January 13, 1973.

The television series, however, was so popular in the UK that after first run episodes were exhausted, the first two novels were reprinted and distributed by London-based publisher Tandem Books, who also released the four additional titles, all in 1976.