(NewsNation) – One person’s trash literally became another person’s treasure after a New Hampshire woman found a valuable painting among the artwork at her local thrift store.

The woman, who was searching for frames, reportedly purchased the artwork for $4. It sat in her home for years — and at one point in her closet — until she posted a photo of the artwork to a Facebook group.

That’s when it caught the eye of art conservator Lauren Lewis, who recognized the painting was an original work by renowned American illustrator N.C. Wyeth dating to 1939.

Lewis has worked with the Wyeth family since 1998, and recognized the painting’s potential significance.

“I happened to be scrolling through one day in mid-May, and I saw photos of this piece with the tagline, ‘Is this real?'” Lewis said. “That happens fairly often, but what intrigued me about this one is she included photos of the back of the painting, and you can see the labels. And so that made me look a little bit closer.”

The lost N.C. Wyeth painting “Ramona” was found at a thrift store in New Hampshire, where its current owner purchased it for just $4. (Bonhams Skinner)

Lewis noticed that the labels and other details appeared authentic. She decided to reach out to the owner, offering to assess the painting’s condition in person.

Upon closer inspection, Lewis determined the piece was indeed an original N.C. Wyeth painting, leaving the owner in shock.

Lewis added that $250,000 is the “going rate” for N.C. Wyeth paintings.

“He was the preeminent illustrator of the early 20th century. And his works are what a lot of people think of when they think of ‘Treasure Island,’ or, you know, some of the other books that he illustrated,” Lewis said. “And so the fact that this painting, which has been missing for 80 years, and suddenly turns up, is just fantastic for the art world.”

When asked about the odds of such a discovery, Lewis described it as a “one in a million” occurrence.

“I’ve never seen something like this happen,” she said. “You hear the urban legends of, you know, finding an original Picasso or at a garage sale or that sort of thing, but this is … something that’s really amazing.”

The painting, titled “Ramona,” was one of four illustrations Wyeth created for Helen Hunt Jackson’s 1939 novel of the same name, the Bonhams Skinner auction house noted in a press release. Only two of the four have been located, according to the release.

“Ramona” is set to go up for auction alongside other pieces of American artwork on Sept. 19. It’s expected to sell for between $150,000 and $250,000, the auction house estimates.