Ben Cartwright's suspicions are aroused when scruffy prospectors Cunningham (Parley Baer) and Furnas (Walter Coy) arrive in town, claiming to have struck a valuable silver lode at Thunderhead Mine. Investigating, Ben discovers that Jim Bronson (Judson Pratt), former owner of the mine, has been murdered. Could the two prospectors be responsible, or is there another sinister figure waiting in the wings? Also in the cast are Ross Elliot as Watkins and the ineluctable Vito Scotti as Leon Flores. Written by Gene L. Coon, "Thunderhead Swindle" made its network debut on April 29, 1961. ~ Hal Erickson, Rovi