AMESBURY, Mass. (AP) – A painting that gathered dust in a cluttered attic for more than a half century fetched more than a million dollars at auction on Sunday.

The century-old painting by Martin Johnson Heade was discovered by Leigh and Leslie Keno last month as they sifted through a treasure trove of valuables at the Arlington Heights home. The Kenos, tipped off by an Amesbury appraiser, were filming an episode of their PBS series “Find!”

The 12-inch by 26-inch river landscape at sunset which features a sailing vessel in the foreground had been stored in the attic, face to the wall, for more than 60 years. The owner wishes to remain anonymous.

The Kenos took the painting to Heade expert Ted Stebbins Jr., head of American Art at Harvard’s Fogg Museum. Stebbins authenticated the piece, which is still in its original gilt frame.

“From the minute we walked in the door, we realized that we had entered a treasure trove of special collectibles, but couldn’t have imagined that we would have found a work by such a pre-eminent artist,” Leslie Keno said.

At auction Sunday, the painting was sold for just over $1 million to New York City gallery owner Michael Altman, who was bidding for a private collector. The sale price was more than double what the Kenos expected.

“It’s a true treasure out of the attic, literally,” Leigh Keno said by phone from the Amesbury Auction House.

“We knew something like this might happen someday on the show. We didn’t think it would happen this quickly.”

The seller is “still recovering,” Leigh Keno said shortly after the auction. “It’s so nice to see great things happen to nice people.”

The painting’s discovery and its auction will be aired on separate episodes of “Find!” in December and January.

Heade, who lived from 1819 to 1904, was virtually unknown in his day, but now is widely recognized as one of the greatest American romantic painters.

“It was determined to be a Newburyport scene,” Leigh Keno said of the painting. “This was one of his favorite areas to paint.”

AP-ES-12-07-03 1526EST