The Massive Underground Antenna That Almost Buried Wisconsin: Inside the Navy's Cold War ELF Communication Project

Wisconsin is famous for cheese, the Green Bay Packers, and being the birthplace of the ice cream sundae—but few know that the state nearly became home to one of the most ambitious and bizarre military projects in American history. During the height of the Cold War, the U.S. Navy proposed Project Sanguine, an audacious plan to blanket 41% of Wisconsin with 6,000 miles of underground cables that would form a giant antenna for communicating with submerged nuclear submarines. The project promised unprecedented military advantage: the ability to send orders to submarines anywhere on Earth without forcing them to surface and risk detection. Yet despite its strategic importance, Project Sanguine never materialized, buried not in Wisconsin soil but in the weight of its staggering cost and fierce public opposition. Instead, the Navy scaled back its ambitions and built Project ELF, a more modest system that would serve as a technological bridge between the Cold War era and the modern world—until it, too, was quietly decommissioned two decades after the Soviet threat had vanished.