A Tuneup for the Lighthouse

Since 1910, Split Rock Lighthouse has shone sentry atop a storybook perch nearly 50 miles up the Lake Superior shore from Duluth. Weather and time have taken a toll on the well-known landmark, which receives 150,000 visitors annually. It spent this spring and early summer shrouded in scaffolding for renovation addressing harmful moisture.

Within Split Rock Lighthouse State Park, the 25 acres containing the lighthouse and its attendant buildings are administered by the Minnesota Historical Society. Site Manager Hayes Scriven says the building’s moisture problems come from being closed for too long, particularly during winter.

“Air is supposed to move through the building and out through the top,” he says. “But what’s happening when the building is closed is that moisture goes into the driest areas. In winter, moisture sits and freezes and thaws.”

The project heads off major damage. If the moisture remained untreated, Scriven says, “the brick and the mortar and concrete would continue to deteriorate, and we would have sections of the building falling apart.”

A spring visit to the lighthouse, which remained open for tours, offered a glimpse into repairs. On a foggy April afternoon, the lighthouse’s pale-yellow exterior was hidden behind scaffolding crews used to repair damaged bricks. Longtime interpreter Ed Maki unlocked the lighthouse door and led a sparse tour group of one through the interior, where bricks were marked for replacement and new ductwork snaked above, soon to be hidden under a false ceiling. In the future, Maki said, a humidity sensor would control the HVAC system and trigger ventilation when moisture levels climb.

Up a spiral staircase, the visitor followed Maki into a round room housing platter-sized gears within a glass-walled box. These gears manipulate the 1,500-pound lighthouse lens above, its carriage floating on a sealed pool of mercury that serves as a bearing. The setup functions “like a huge clock,” Maki said. (Accordingly, the Historical Society once hired a local watchmaker to fix it.) Looking up, visitors can glimpse the star of the show, the light itself. The massive lens is original, made in Paris before World War I. Once illuminated by kerosene, it was electrified in 1940 with a 1,000-watt bulb.

Standing watch for more than a century, the lighthouse has come to be more than a safety beacon.

“Split Rock Lighthouse means a lot to people who see it as an iconic symbol of Minnesota,” says Scriven. “If you think of Minnesota, you think of that view of Split Rock, and I think there’s a lot to that.”

Renovations were expected to wrap up in June, with scaffolding giving way to that familiar scene.