At the time it aired, James Arness was 64, twice the age he was (32) when he started 'Gunsmoke' in 1955.
James Arness admitted for wanting to do this TV film/reunion very badly. When he was asked on how Gunsmoke (1955)'s 20-season, 635-episode series ended, he said "We didn't do a final wrap-up show. We finished the 20th year, we all expected to go on for another season, or two or three. The network never told anybody they were thinking of canceling us".
James Arness, Amanda Blake, Buck Taylor, Fran Ryan, and Steve Forrest reprised their roles from the original series.
Ken Curtis was originally offered to reprise his role as Festus, but declined since CBS refused to match his asking price.