The website cover image is a subset taken from Virgil Williams, View of Mt. Katahdin from the West Bank of the Penobscot River, 1870, oil on canvas, 26 1/4 x 40 in. Colby College Museum of Art. The Lunder Collection, 001.2008
The full image:

The website cover image is a subset taken from Virgil Williams, View of Mt. Katahdin from the West Bank of the Penobscot River, 1870, oil on canvas, 26 1/4 x 40 in. Colby College Museum of Art. The Lunder Collection, 001.2008
The full image: