The Soo Locks at Sault Ste. Marie were among the most strategically vital structures in wartime America. Iron ore from Minnesota's ranges passed through those narrow channels on its way to the steel mills feeding the war machine. Losing the locks would have crippled the entire industrial effort. So in the early 1940s, after the Pearl Harbor attack galvanized the nation, the government carved an airfield out of the Upper Peninsula wilderness at the tiny crossroads of Raco. Three runways, each 5,520 feet long and 300 feet wide, were laid in a triangular pattern. Dozens of aircraft dispersal pads were built among the surrounding trees, designed to scatter planes so a single bombing run could not destroy them all. Designated Raco Auxiliary Airfield, it served as a refueling stop for aircraft bound for Alaska and as a defense post for the locks. Yet no tactical fighter units ever operated from the field during the war. A skeleton support crew from the 4250th Army Air Force Base Unit at Alpena kept the lights on, and by 1945 the base fell silent.

Silence did not last. The Cold War demanded new defenses, and the Army found a creative second use for Raco's infrastructure. Former taxiways became roads, and more than two dozen aircraft dispersal pads were reshaped into circular artillery positions for 75-mm Skysweeper anti-aircraft guns. These rapid-fire, radar-guided weapons were designed to shred low-flying Soviet bombers before they could reach the Soo Locks and the vulnerable shipping narrows. By the mid-1950s, eight Skysweeper battalions were deployed at Raco, their barrels pointed skyward above the treeline. But technology was already overtaking them. The Nike Ajax missile system was coming online across the country, and K. I. Sawyer Air Force Base opened in 1956 with fighter-interceptors that could cover the same airspace faster and at greater range. Battery by battery, the Skysweepers were withdrawn. By the end of 1957, the Army abandoned Raco again.

The Air Force moved in almost immediately. East of the old runways, construction crews built a rectangular installation for something far more powerful than any gun: the CIM-10 Bomarc, the first long-range surface-to-air missile in the world. These supersonic, ramjet-powered interceptors could carry either conventional or nuclear warheads and were designed to destroy entire formations of enemy bombers before they reached American cities. On March 1, 1960, the 37th Air Defense Missile Squadron activated with 28 Bomarc missiles, the advanced IM-99B variant. Only about 40 personnel staffed the site, which was officially designated the Kincheloe AFB BOMARC site, linked to the larger air base 17 miles to the east. For twelve years, these missiles stood ready on hair-trigger alert, part of a continental defense perimeter stretching from coast to coast. They were finally inactivated on July 31, 1972, the last chapter of Raco's military service.

After the Air Force departed, the property passed to the United States Forest Service and became part of the Hiawatha National Forest. But those expanses of old military concrete and the punishing Upper Peninsula winters attracted a surprising tenant. Smithers-RAPRA leased the site and transformed it into the Smithers Winter Test Center, one of the world's premier cold-weather proving grounds. The facility sprawls across more than 750 acres of snow-packed and ice-covered surfaces, with approximately 40 acres of maintained ice alone. Over 40 employees work through the brutal winters to groom 30 separate testing areas for everything from compact cars to Class 8 semi-trucks, military vehicles, construction equipment, and snowmobiles. Automakers and parts suppliers from around the world send their latest prototypes here, wrapped in camouflage wrap to foil spy photographers, sliding and spinning across the same ground where Skysweepers once tracked phantom bombers.

Flying over Raco today, the old triangular runway pattern is still visible through the forest canopy, a ghostly imprint of wartime urgency. The circular artillery pads dot the woods like crop circles. The rectangular BOMARC installation sits silent to the east. And across the ice-testing grounds, tire tracks trace endless loops on frozen surfaces that once launched missiles toward the stratosphere. Environmental investigations have catalogued the contamination left behind by decades of military activity, the residue of jet fuel, missile propellant, and gun oil slowly being absorbed by the northern Michigan earth. Raco Army Airfield is a place where each layer of American defense history left its mark on the landscape, from propeller-driven transports to nuclear-tipped missiles to, improbably, the next generation of winter tires.