For Joe Laurin on Lake of the Woods, exploring beats fishing any day.

While his wife, Anita, is catching walleyes, he’s dreaming about the next waypoint for his app — a digital guide to more than 130 special places steeped in history, mystery, ecology and more.

This year on July 4th, the Polaris Industries powertrain engineer unveiled an iPhone app that he’s been researching on his own for years. He’s traveled thousands of miles on the border lake in search of abandoned gold mines, old prisoner of war camps, hidden waterfalls, beaches, rope swings, pictographs, rock carvings, hiking trails and pathways to adjacent lakes. The searchable app briefly describes each site, provides a photo and pinpoints it with GPS coordinates.

“It’s a labor of love,’’ said Laurin, a Chicago native who has lived in Roseau since 1990. “Best lake in the world … with all kinds of crazy history.’’

Laurin’s app, recently expanded for Android systems, marks some well-known fishing holes. But it’s intended more as a diversion for anglers who want to break up their days. Ideally, he said, it would draw non-anglers to the 30-by-60-mile waterway, textured with more than 14,400 islands.

Since early July, Laurin already has added 30 new sites to the app. One of those is Three Friends Mine near Clearwater Bay, west of Keewatin, Ontario.

“You step on shore and there’s the mine shaft,’’ Laurin said.

His study of the lake’s gold mining heritage has uncovered a dozen mines so far that he has loaded onto the app. He found some of them by reckoning from a 1930s Canadian map. Abandoned rock crushers, hauling bins and other equipment litter the locations.

Laurin also studied Canada’s cooperation with England during World War II, exploring excavated shoreline places on Lake of the Woods that served as prisoner of war camps. He’s found horse bones, shoes, saw blades — even a diving board. Prisoners commonly cut wood at the camps.

Painted Rock is an American Indian pictograph located in Painted Rock Channel, northwest of the harbors in Morson, Ontario. On a recent fishing trip to Miles Bay, our own group of eight anglers put our walleye pursuits on hold to search for it.

Wi-Fi signals on Lake of the Woods are hit and miss and the app works without Wi-Fi assistance. But you need a device separate from the app to navigate to the given GPS coordinates. Inside the remote Painted Rock Channel, we imagined how the surrounding islands, forest and bluffs had the makings for a settlement long ago. The red and orange pictograph, still vivid in parts, includes a drawing of a medicine man, Laurin said. It’s a place we never would have discovered without the app.

Laurin attended Winona State University and joined Polaris as a mechanical engineer. At the company’s Roseau plant, he oversees a 30-member department. Twenty years ago, he and his wife bought land on Flag Island near Angle Inlet at the northern edge of Minnesota’s “chimney’’ appendage.

In 2008, they built a landmark of their own by constructing a lakeshore cabin shaped like a lighthouse. The timbers were hauled in via semi-truck when the surrounding bay was covered with 3 feet of ice. Now, when curious passersby stop, they get a tour if the Laurins are home.

“Everyone thinks it’s public,’’ he said. “We don’t mind.’’

When it’s time to explore the lake, Laurin is most often on his 300-horsepower personal watercraft. On calm water, the machine cruises at 70 mph. He skips across the shallows with no worries.

“You get to places quick,’’ he said.

In the town of Angle Inlet, the community recently created a marker buoy near the lake’s shore. It was patterned closely after a “sister’’ marker in Key West, Fla. Laurin chose the blue and yellow Angle Inlet buoy as the icon for his app. It unofficially marks the “northernmost point in the contiguous U. S. A’’ and has become the town’s favorite photo backdrop for visitors.

“I don’t really care to fish, but I love this place,’’ he said. “It’s a tough place not to be at.’’

Laurin’s app isn’t free. He’s charging $19.99 for the download in hopes of recovering the cost of his project. In the first two months, he said, he has sold about 200 copies.