Bass Harbor, ME HL 477 2007 summer Release Open Edition Built on the southwestern point of Mount Desert Island, with an appropriation of $5,000 from the United States Congress, Bass Head Harbor Light answered the call of the US Lighthouse Board to help mariners navigate “a very good harbor.” Lit in 1858, Bass Harbor Head Light, a 32’ tower with a focal point of 56’ assisted mariners in navigating Bass Harbor and marked the entrance to Blue Hill Bay. The original optic was a Fifth Order Fresnel Lens that was later replaced by a more powerful Fourth Order Lens in 1902. The lens characteristic is oscillating red 4 seconds (three seconds red, then one second darkness) that remains in operation today.