To rustle horses from a federally protected area, a crooked cattleman paints his steed to look like a wild stallion, and then tramples a nosy sheriff under hoof and pins the crime on an innocent nag in "Hit the Saddle." Stars the Three Mesquiteers (Robert Livingston, Max Terhune and Ray Corrigan) and a young Rita Cansino (Hayworth). Next, in "Heart of the Rockies," there's a kind of hush all over the plains tonight when Herman's Mountaineers give a leg up to the Three Mesquiteers, who are caughtin a flap with park rangers over the death of a bear. Livingston, Corrigan and Terhune star. 112 min. total. Standard; Soundtrack: English.