William Conrad, who also was the narrator of "Rocky and Bullwinkle" played Marshall Matt Dillon. Mr. Conrad would later do the television series "Cannon" and "Jake and the Fatman" (from which the long-running CBS series "Diagnosis Murder" was spun-off.) James Arness (brother of "Mission:Impossible" star Peter Graves) played Dillon in the long-running (1955-75) TV series (and three subsequent TV movies,) after John Wayne had turned it down.

John Wayne was the one who suggested that James
Arness take the role of Matt Dillon when it went
from Radio to Tv,he also introduced the pilot
when it aired.

Gunsmoke was probably the most popular Western
of all time on either Radio or Tv lasting in it's
Tv version for some 20 years.

Thought I'd note that today is William Conrad's birthday. Were he still alive, he'd be 82.