By the time the New Presque Isle Light Tower was erected in 1870, Presque Isle Harbor was a routine stop for many vessels conducting trade along the Lake Huron shoreline. A natural harbor of refuge, Presque Isle also provided safe and welcome shelter from sudden and powerful storms. The New Presque Isle Light Tower alerted the mariners to impending dangers while the two smaller Range Lights guided them safely into harbor. When the lights were aligned, the mariner knew the safest and easiest path into-or out of-the harbor. The rear range light included living quarters for a keeper and family and is now a private residence. Modern, automated lights have replaced historic ones, but most of the original structures remain. The old front range light was relocated to the entrance of the Old Presque Isle Lighthouse grounds, where it stood for many years. It was moved back to near its original location in 2004 and there faithfully restored. The grave of Adeline Sims, wife of range light Keeper William Sims, is located to the side of the keeper's path in a small, fenced-in area. Legend has it that while her husband and fellow Masons held meetings in the rear range light, she overheard and memorized secret passages. To seal her lips, she was made a member. Adeline Sims died an invalid in 1881, and was buried with a Masonic emblem on her gravestone. Sims is the only woman so honored by the Masons.