Leave it to the brass to stir up trouble. In a way, that was Brigadier General Selmon Wells’ job. The inspector general of the Strategic Air Command always wanted to make sure his airmen could handle whatever crisis might explode on their airbase. He wasted no time in setting off a few of these smoke bombs after landing at Loring Air Force Base in Limestone back in 1961, launching a full-scale drill less than two weeks after the failed Bay of Pigs invasion.

A live warhead, at far left, had already been loaded onto the B-52 in the background when LIFE magazine photographer Leonard McCombe captured Wells standing amid the smoke, like a military version of the Marlboro Man. (McCombe was already famous for capturing the iconic image of cowboy C.H. Long that would go on to sell millions of packs of cigarettes.) By the time this whole three-day operation was complete, several of Loring’s thirty jet bombers would fly more than six thousand miles, dropping a mock bomb in Kansas before returning home to northern Maine.

Exercises like this one were essential to keeping the crews at Loring on their toes, and in the early 1960s the eight-year-old base — the closest one to Europe and Khrushchev’s armies — was one of the most important military installations in the country. Though the Limestone facility was marked for closure fifteen years after this photograph was made, it would take until 1994 before it said goodbye to its last uniformed officer. During the intervening years the base gained the dubious distinction of becoming the first location dedicated to assembling, testing, and storing atomic weapons.

Fast-forward nearly twenty years, and once again a Maine military base faces its final days. This June the Brunswick Naval Air Station starts a new life as an executive airport and business-incubation center. Unlike Loring, which saw hard times immediately after its closure, Brunswick has seen local people working on a redevelopment plan even before the navy sets sail this month. The former base will soon house an aircraft manufacturer, a satellite campus of Southern Maine Community College, an information technology company, and scores more businesses.

Like its counterpart in Limestone, the Brunswick military base will soon cease to exist except in memories — and nostalgic photos like this one.