Bat Masterson is portrayed as being much younger than Wyatt Earp. In fact, there was only a 5 year difference in their ages with Earp being born in 1848 and Masterson in 1853, so by 1874 Earp was 26 and Masterson 21. The actors were 9 years apart in age, with Hugh O'Brian being born in 1925 and Mason Alan Dinehart being born in 1936, which made them ages 30 and 21 as of 1955.
First of 21 series appearances for both Don Haggerty and Ralph Sanford. Haggerty will play Wichita newspaperman Marsh Murdock in 19 episodes, then return a couple years later to play two unrelated character roles. Sanford, who played burly Bartender Larsen, will appear as three different characters before settling into the recurring role of Mayor Jim Kelley for 17 episodes beginning in the fourth season.