Ponderosa ranchhand Dusty Rhodes (Lou Frizzell) has landed in jail. The only man who can clear Dusty is an itinerant, ill-tempered wrestler named Tom Callahan (Victor French), who is nowhere to be found. While searching for the reluctant witness, Joe Cartwright not only runs afoul of Callahan but also Callahan's girl Evangeline (Sandy Duncan in her TV debut), a deceptively frail-looking lass who is capable of smashing barrels with her head! Written by Preston Wood, "An Earthquake Called Callahan" originally aired on April 11, 1971, as the final episode of Bonanza's twelfth season. ~ Hal Erickson, Rovi