Working lighthouses are still found along the Atlantic and Pacific coasts, in the Great Lakes region, along major rivers like the Mississippi, and in the Gulf of Mexico. Most are automated, using a combination of light and sound to warn ships of dangerous reefs and shorelines.
The one exception to automation is the Boston Lighthouse on Little Brewster Island, Boston Harbor, Massachusetts. It is the oldest light station in the country, completed in 1783. Congress passed a law making the site a living museum, and as such it is a permanently staffed station. The keeper turns the light on every night and off every morning.
Sandy Hook Lighthouse, built in 1764, is the oldest lighthouse tower. It sits on the New Jersey side of New York Harbor, is a National Historic Monument and is fully automated. For a while New Jersey and New York both claimed ownership of Sandy Hook. The Federal Government stepped in and took over jurisdiction.
Notable lighthouses on the Pacific Coast include Pigeon Point, in San Mateo County, California, built in 1872 and now a state park. The Alcatraz Lighthouse, established in 1855 and on the grounds of the once infamous prison, is in the middle of San Francisco Bay. The U.S. National Park Service offers ferry tours from Fisherman's Wharf.