Racehorse-owner Dan Morgan is ruled off the track and out of racing when his horse is doped by a rival owner who knows that Dan's horse can win a high-stakes race. Trying to clear his name, Dan runs into many difficulties and incidents, including a blazing barn filled with valuable horses, before he is able to gather the needed evidence against the guilty man.

The U.S. Army needs more horses for the Spanish-American War. Hoppy must turn his Bar 20 cowhands into Rough Riders to gather up the horses, and of course bad guys try to sabotage the operation.

An evil gang is involved in both cattle rustling and the robbing of stagecoaches. Hoppy must stop them without help from the sheriff who turns out be a major outlaw himself.