Deer Isle Thorofare (Mark Island) Lighthouse
A square white brick lighthouse on Mark Island, active since 1857, now owned by Island Heritage Trust. You can't walk to it — it's an island — but you can see it from Sand Beach Road or pass it on the ferry to Isle au Haut.
The Deer Isle Thorofare Light was built in 1857 to guide ships through the narrow passage south of Stonington, at a time when Deer Isle's granite quarries were supplying stone for buildings up and down the eastern seaboard. The square white brick tower with its granite foundation and black cast iron lantern sits 105 feet above the waterline on Mark Island, about 1.8 nautical miles west-southwest of Stonington.
The lighthouse was automated in 1958 and remains an active aid to navigation — still useful to the lobster fleet and passing yachts working Merchant Row. In 1998, after roughly 140 years of federal operation, it transferred to Island Heritage Trust through Maine's Lights Program, which redistributed 36 Maine lighthouses to responsible local groups. IHT has maintained the property since.
The tower's history includes some memorable keepers: Allan Holt was known for towing distressed vessels to safety. And in 1935, when Keeper Conary suffered an apparent heart attack, a lifeboat crew had to row through frozen harbor ice to evacuate him to the mainland.
The grounds are technically open to visitors, though the tower itself is closed. Getting there requires a boat.
What Visitors Say
"Beautiful stop with epic Maine coastal views."
"It's barely visible and the viewing area is an industrial site"
"From Stoningham island you can see it in the distance. You can hear it better than see it. Zoomed photo shows what to look for."
Local Tips
- Viewable from Sand Beach Road on Stonington's south shore — bring binoculars.
- The Isle au Haut ferry (from Stonington town dock) passes close; a trip over gives the best view without a private boat.
- Sea Kayak Stonington runs guided trips through Merchant Row; Mark Island is a visible landmark on those routes.
- IHT holds ownership — if you want to land on the island, check with them directly for current access status.
Connected To
- Sea Kayak Stonington — guided kayak trips through the Stonington archipelago pass near Mark Island
- Stonington Public Landing — the ferry to Isle au Haut departs from here; closest mainland vantage
- Sand Beach — Sand Beach Road offers views of the lighthouse from shore
- Settlement Quarry Preserve — another site connected to the granite era; the quarry supplied stone for major buildings during the same period