Libby Island Light This 120 acre island is actually two islands seperated by a sandbar. Known for years as Machias Light it is the eastern most light in the U.S. The 42 foot tower was built on the southern tip in 1824. A 1 1/2 story wood keeper's house was also built at this time. A Fresnel lens was installed in 1855, and a fog horn in 1884 because it was one of the foggiest locations along the Maine coast. Among the more notable ship wrecks in the area was the Caledonia, out of Nova Scotia, in 1878.