It is now an accepted fact that the best of Johnny Mack Brown's Universal westerns were directed by the talented Joseph H. Lewis. Boss of Hangtown Mesa may not be in the same league as the Brown-Lewis classic Arizona Cyclone, but it comes awfully close. This time around, hero Steve Collins (Brown) comes to the aid of Betty Wilkins (Helen Deverell), who has taken over the telegraph-line business established by her uncle John (Henry Hall). The latter was murdered by outlaws who don't cotton to having the territory linked up electronically with the rest of the world.

A cowboy heads for the town where his father was murdered to find out who was responsible.

To investigate a gold-shipping scam, a postal inspector goes undercover and tries to infiltrate the gang he believes is responsible.