Goofs and Saddles (1937)

Set in the old west, the stooges are spies for US Calvary; "Buffalo Bilious", "Wild Bill Hiccup" and "Just Plain Bill". Sent by General "Muster" to catch a gang of cattle rustlers, they wind up in a saloon where the boss of the gang hangs out. The boys disguise themselves as gamblers and get into a card game with the villain, but must flee when their identities are discovered. They hole up in a cabin, fighting off the bad guys, until the calvary arrives.