Six years ago, the unknown shopper was looking for scrap frames in Manchester and found a fairly basic one surrounding an oil painting. That painting, it turns out, was a lost work by the American great N.C. Wyeth—and it’s expected to fetch between $150,000 and $250,000 at an upcoming auction. Bonhams Skinner will put it up for bids on Sept. 19.

It’s not just the trash-to-treasure element that makes this story unique. If it wasn’t for a Facebook group, the painting might well have stayed hidden for many more years.

The owner, after purchasing the work of art, took a liking to it and hung it in her room instead of discarding the artwork for the frame. She joked about it being an authentic Wyeth and did a perfunctory internet search, but didn’t find anything.

Then, earlier this year, she posted a picture to the Facebook group “Things Found In Walls” on a whim. A user suggested she post the images to a Wyeth-specific group, where an expert took notice.

They got together about a month later, when it was authenticated.

The painting, says Lauren Lewis, the expert who authenticated it, is “in amazing condition, especially considering it’s been missing for 80 years.”

N.C. Wyeth was one of America’s best-known painters in the early 20th century. He was especially well known for illustrating books—and in the 1930s, Little, Brown and Co. contracted him to produce four paintings for the release of Ramona by Helen Hunt Jackson. The book told the story of a half-Scottish, half-Native American orphan.

Wyeth delivered the paintings; the trail went cold from that point. Bonhams Skinner speculates this painting “likely was gifted by Little, Brown and Company publishers to an editor or to the estate of the author.”