The New Dungeness Lighthouse has guided mariners the longest natural sand spit in the United States since 1857.  U.S. Coast Guard photo. SEQUIM, Washington – The New Dungeness Lighthouse has guided mariners around the longest natural sand spit in the United States since 1857. The storied beacon has welcomed mariners into the Puget Sound since it was first lit on Dec. 14, 1857, more than 30 years...