Bass Harbor Head Light stands at the southernmost tip of Mount Desert Island and marks the entrance to Blue Hill Bay and Bass Harbor. Since 1858 it has warned mariners of navigational hazards along this rocky shore. In the nineteenth century, the waters near this light station bustled with merchant ships, fishing vessels, and schooners carrying granite, fish, lumber, and lyme to distant ports or bringing goods from around the world back to Maine. Many of the visible islands were once inhabited by people who made their living from the surrounding sea, and by 1860 nearly one in five Maine residents was a mariner. Today, Swans Island is the only island in view with a year-around population. As ships and commerce have changed, the light station has been automated but never darkened; built in 1858, it stands 56 feet above mean high water, has a maximum visibility of 13 nautical miles, shows a red occulting light with four seconds on and one second off through a 4th Order Fresnel Classical lens, and has been automated since 1974. The light is maintained by the U.S. Coast Guard, the small building east of the lighthouse was built in 1897 and housed the fog signal, and the keeper’s quarters serves as a U.S. Coast Guard residence.