Smugglers are working the border between Mexico and California in this action-filled and, of course, tuneful Gene Autry Western. Autry, sidekick Sterling Holloway, and the Cass County Boys get involved with fiery Elena Del Rio (Adele Mara), a singer in the local cantina who alternately throws knives at them and helps catch a gang of jewel smugglers taking advantage of local refugees. Chasing in and out of Joshua Tree National Monument, our heroes go up against a couple of supposedly law-abiding citizens, a peon (Martin Garralaga) who isn't what he pretends to be, and the local rural residents. Happily, everyone takes time out from the mayhem to perform Jack Elliott's "Twilight on the Rio Grande" and "The Pretty Knife Grinder," Smiley Burnette's "It's My Lazy Day" and "Great Grand Dad," Nat Simon and Charles Tobias' "The Old Lamplighter" and a couple of other selections. In addition to Joshua Tree National Monument, Twilight on the Rio Grande was filmed at Victorville, CA.
by Hans J. Wollstein synopsis