In 1962, in the woods outside Moncton, New Brunswick, around 160 miles east of the Maine border, David McPherson Sr. found a very large white box adorned with some very large lenses. It was attached to a parachute, so McPherson thought it might be an American spy camera, possibly launched by the Central Intelligence Agency. The fact that Canadian military tried to take the box from him—before McPherson and his family voluntarily relinquished it in exchange for answers that never came—only added to his suspicions.

McPherson died 18 months ago, never having gotten to the bottom of the mystery. But this week his son, David McPherson Jr., said that his father had been right all along. Declassified CIA documents reveal that the white box was part of a CIA program to send cameras into the sky with balloons to spy on the Soviets. The McPhersons’ box likely hit some wind and went astray.

“I guess looking back now,” McPherson Jr. told the CBC, “the army probably had no choice—they couldn’t tell us what it was.”

The CBC helped the McPhersons crack the mystery after running a story Monday about the “thing in the woods.” A rush of tips soon came in, leading the family to some declassified documents on the CIA website, in addition to the Military Communications and Electronics Museum in Kingston, Ontario, both of which had photos of apparatuses that looked like the one they had found. Documents also reveal that the box was likely part of Project Genetrix, a program started under President Dwight D. Eisenhower that used balloons to conduct surveillance over Russia and China, according to the CBC.

It’s unclear where the box is now—maybe in a government warehouse somewhere—but the McPhersons still have some two-dozen photos from its discovery. They also now have closure.

“I never thought it was a weather balloon,” James Rogers, who, as a 19-year-old, helped David McPherson Sr. carry the box out of the woods, said. “Otherwise everyone wouldn’t have been so secretive about it.”