Photographer Kati Dimoff has developed a curious habit. Whenever she enters a thrift shop, she makes a B-line for the used camera section and checks each and every 35mm camera for exposed but undeveloped rolls of film. Recently, this habit yielded an incredible discovery.

On May 26th, Dimoff found herself in southeast Portland, Oregon. And as is her habit, she stopped by a charity shop to have a look at their film cameras. This time, she struck gold.

"I found an Argus C2—which would have been produced around 1938—and it had a damaged roll of kodachrome slide film in it," she told dpreview over email. Naturally, she bought it and took it to the folks at her local developer to have it developed.

Kati tells us her local developer, Blue Moon Camera is one of the last places to get old, expired, and out-of-production film processed, and though they couldn't breathe colour back into the iconic Kodachrome film—the developing chemicals were discontinued years ago—they were able to develop the roll in black and white. What awaited her when she picked up the prints was a short note.

"Blue Moon developed it for me," she tells us, "and when I picked up the prints on Monday, June 12th, there was a note on the package that said, 'Is this from the Mount St. Helens eruption?'"

It was. Three of the photos on the roll were taken on or around that fateful day in 1980 when Mount St. Helens erupted violently - considered by many to be the most disastrous volcanic eruption the United States has ever seen.

There were three photos in all. The first, which Dimoff says was likely taken from Highway 30, shows St. Helens in the distance with just a puff of ash coming out from the top. That photo may have been taken during the two months prior to the eruption, when the volcano was occasionally causing earthquakes and venting steam.

The other two photos are more striking. Captured from in front of John Gumm elementary school in St. Helens, Oregon, they show a massive ash cloud—mushroom-like and dramatic.

But this story doesn't end with three never-before-seen photos of a historic event captured in 1980 and re-discovered in a thrift shop in 2017 (even though that would be enough for us). There was another photograph on the roll: a family portrait.

This photo actually helped Dimoff to identify the owner of the camera. Pictured are Mel Purvis, his wife Karen, his grandmother Faye, and his son Tristan. Mel saw the portrait in The Oregonian and reached out to the paper, who put him in touch with Dimoff.

Now, his grandma's camera, negatives, and prints are on their way back to their rightful owner.

Sources: DPReview, Gizmodo