Painting No. 24349 turns out to be Renoir's painting "Paysage Bords de Seine,'' which translates to Banks of the River Seine, Craner determined. It dates to about 1879 and measures 6 inches by 10 inches.
The painting is set for auction Sept. 29. It could fetch $75,000 or more, Craner said.
Elizabeth Wainstein, owner of the Potomack Co., said there's no doubt about the painting's authenticity.
The Shenandoah Valley woman who found the painting and kept it in storage for nearly two years has declined to publicly disclose her name.
After weeks of research, Craner believes Renoir gave the painting to a woman who modeled for him. The painting was then sold to the Bernheim-Jeune art gallery for 5,000 francs in 1925, according to gallery records. The following year, the gallery sold the painting to American lawyer Herbert L. May who kept homes in New York and Geneva and also worked for the government in Washington.
As far as Craner can tell, May kept the painting in his personal collection until his death in 1966. It's a mystery, though, as to how the painting ended up in West Virginia. Still, its provenance is fairly short as the painting has not traded hands many times.
"It just did what paintings do sometimes -- they kind of disappear out of circulation,'' Craner said. "That's what is so fantastic. This painting's been unseen since 1926.''