Western anthology starring Jim Davis as Matt Clark, a detective for the Southwestern Railroad who tracked down notorious frontier outlaws over a period of forty years with the assistance of his lovely female helpers Frankie Adams (Mary Castle) and later Margaret "Jonesy" Jones (Kristine Miller) who traveled ahead to a town or region and gathered intelligence before Matt came on the scene.

The outlaws and bandits sought by Matt and his sidekicks included:

• Marie Windsor as Belle Starr.
• Richard Jaeckel as Billy the Kid.
• Arthur Space as Black Bart.
• Jack Elam as Black Jack Ketchum.
• Joe Sawyer as Butch Cassidy.
• Jean Parker as Cattle Kate, a cattle rustler.
• Myron Healey as Dalton brother, Bob
• Robert Bray as Dalton brother, Emmett
• Fess Parker as Dalton brother, Grat
• John Mooney as Dalton brother, Bill
• Steve Brodie as Harry Tracy, a psycho killer.
• Greg Palmer as Jack Slade.
• Richard Travis as James brother, Frank.
• Lee Van Cleef as James brother, Jesse.
• Richard Webb as John Wesley Hardin.
• Donald Curtis as Johnny Ringo.
• Rick Jason as Juaquin Murietta, a Mexican bandit.
• Veda Ann Borg as Kate Bender.
• Gloria Winters as Little Britches.
• Don Haggerty as Sam Bass.
• Slim Pickens as The Smiling Kid.
• George Wallace as Younger brother, Cole.
• Sheb Wooley as Younger brother, Jim.
• Gregory Walcott as Younger brother, John.

Matt's career spanned from the 1860s to the early 1900s. In one of his earlier adventures, Matt spied for the Union army in 1863 to investigate suspicions that Quantrill (Bruce Bennett), the guerilla fighter was linked to an assassination plan of Abraham Lincoln.

Then, in 1903, Matt (who appears to look the same as he did in the 1860s) was on the trail of Tom Horn (Louis Jean Heydt), a once famous detective who turned killer during the Wyoming range wars.

Throughout his career, Matt held one consistent thought about those he brought to justice: "I don't care how right a man is. As soon as he picks up a gun, he's wrong from the start!"