She said while she was aware she sounded like a "total lunatic", she believed the painting was "homesick" and should be returned to New Zealand.
"It doesn't belong in North Carolina here among the pine trees and Republicans.
"I am a completely lucid woman and not at all given to flights of fancy, but I am quite sure this painting wants to be reunited with the family of the artist."
Ms McLean said she lived in New Zealand when she was younger, including in Whakatane and the Wellington region.
She bought the painting about nine years ago from an antique store in Petone.
"After my father died I came back to New Zealand to help my mother and sort his things out. I wanted a souvenir to take back to the United States as I didn't know when I would next be in New Zealand."
Dr Duncan was born in Christchurch in 1881 and later moved to Rotorua, working for the health department.
He had no formal training as an artist and spent time in Sydney and Europe.
Dr Duncan may have been married to a woman named Gladys King Overton, Ms McLean said.
If so, his children were Brian Duncan, John Cam and Margaret King Duncan.
Ms McLean has tried to find Dr Duncan's descendants.
"I have already written to the lovely folks at the Rotorua Geneology branch [of the New Zealand Society of Genealogists] asking if they could find his descendants, and they are being so helpful, but so far no descendants have popped up.
"Maybe some older readers will remember Dr Duncan, as he was well known in Rotorua."
Mary Ann Cameron, secretary of the Rotorua Geneology branch, said group members had asked contacts and tried different avenues but had "drawn blanks".
Ms McLean also wanted to know the exact location of the landscape shown in The Lonely Lake.
"I know from research that the location is the Rotorua area, but where?"
She was drawn to the mountain range in the painting and believed it was Mt Tarawera which she had climbed in her youth.
"I am sure that one of your readers will go 'Aha' the moment they see the painting."
Ms McLean said she was grateful for the help people had offered in the search so far.
Dr Duncan won the Bledisloe Medal for landscape of the year in 1934.
He painted other works depicting the Rotorua district landscape, including Landscape, Rotorua, now in the Fletcher Collection.
His paintings were also exhibited in the Auckland Art Gallery and Sarjeant Gallery in Whanganui.
If you know how to contact Dr Duncan's descendants - or can confirm which lake is in the painting - contact editor@dailypost.co.nz.
