This early Monogram entry has Bob Harding, played by the personable Bob Steele, off to find the titular - and long lost - Hidden Valley which is believed to be rich in valuable turquoise. In true B western tradition, he feels that he must make his fortune before asking for the hand of the fair Joyce (Gertrude Messinger).
Unfortunately, on the way, his travelling companion, an eminent archaeologist, is murdered and Bob is falsely accused, tried and sentenced to hang. Of course, we all know that Bob is innocent of the dastardly deed and that the real villains of the piece are Frank Gavin (Francis McDonald) and his swarthy, scowling henchmen.
When our hero goes on the run, there is much chasing around on horseback by the sheriff and his posse, the bad guys and, last but not least,Joyce's weak and easily led brother Jimmie (played with hugely melodramatic relish by Ray Hallor) who has the map showing the location of Hidden Valley.
This is, in some ways, an above average B western. Directed competently, as always, by Robert N. Bradbury (Bob's father), there are some unusually good location shots and genuinely original ideas, not the least of which is the use of a Goodyear blimp as a means of tracking down the wanted man. On the debit side, however, even allowing for the vagaries and implausibilities of the genre, I would have hoped for just a few of the loose ends to have been tied up at the finish. Not a classic, therefore, but a passable way to spend an hour.
Incidentally, look out for George Hayes, in his pre-Gabby days, as one of Gavin's unshaven heavies. Yer durned tootin'!