Standing 1,475 feet above the ocean at the quiet rocky outlet of Lake Itasca in Minnesota's oldest state park, the mighty Mississippi begins its 2,552-mile journey to the Gulf of Mexico — and a traveler named Yola couldn't resist wading across it and sending word to her friend Ella in St. Louis. This richly colored linen-era card captures the serene headwaters at golden hour, a dark interpretive obelisk at right bearing the famous inscription about the river's winding course south. Postmarked Cass Lake / Cass Lake State Park, Minnesota, August 13, 1950, with a US 2¢ red Jefferson stamp affixed, Yola's message is buoyantly brief: "We waded across the source of the great Mississippi River today. Having a swell time." Published by Curteich-Chicago for Northern Minnesota Novelties of Crosslake, MN — a classic mid-century American travel memento.