Hopalong Cassidy #121

In "Theft of the Treasure Horses!", Hopalong Cassidy races to recover a stolen herd of prized horses, only to find the thieves have already vanished into the desert with a map to a hidden gold cache. When he tracks them to the buried mine, he’s trapped in a forgotten mine shaft—but with quick thinking, he uncovers an underground river and uses it to escape. Meanwhile, the outlaws, weakened by poisoned water, are stranded and desperate as the desert closes in.