Box Sixteen Sixty-Three: The City That Didn't Exist

If you mailed a letter to someone who lived in the most important city in the world in nineteen forty-four, you would have addressed the envelope to a post office box in Santa Fe, New Mexico. Box sixteen sixty-three. No city. No street. No return address that named a real place.

In nineteen forty-three, the United States Army acquired the Los Alamos Ranch School, a boys' preparatory school on the Pajarito Plateau in the Jemez Mountains, evicted the students and faculty, fenced the mesa, and classified the location. Within eighteen months, ten thousand people lived there. Scientists arrived from universities across the country, from Britain, from Canada, from countries that had ceased to exist. They were assigned code names in official documents. Residents married under names that did not match their identification papers. Children were born there, and their birth certificates listed Santa Fe as the city of birth, because Los Alamos did not officially exist.

Cars registered to residents of the classified city bore identical license plates, a flat-sided plate stamped with a number that traced back to no particular address. If you had driven behind two or three such vehicles in Santa Fe, you would have noticed. Many people did.

The post office box in Santa Fe was the one geographic anchor residents could publicly share. Scientists writing to colleagues at other universities, physicians writing to family, children writing to grandparents: all of it went out under Box sixteen sixty-three.

The mesa itself, the Pajarito Plateau, had been home to Pueblo communities for centuries before the Ranch School arrived. The families who farmed the valley below were aware that something had changed when the Army trucks started coming.

The city on the mesa produced the Trinity device in July nineteen forty-five. It produced the bombs that ended the war in the Pacific. Los Alamos National Laboratory is still there, still operating, still classified in significant portions. The post office in town now accepts addresses.