On this, my first trip to the Land of 10,000 Lakes, I pictured Minnesota when my grandparents were teenagers, in the 1930s. Flat land and timber, country churches and little white houses with big gardens, dirt roads, a dusty Model A in a gravel driveway, kids with fishing poles.

On the highway headed north from Duluth to International Falls, we passed cars with canoes on top and rigs with boats in tow. At every intersection, a sign pointed the way to another lake.

Our destination was Rainy Lake in Voyageurs National Park, named for the hardy French Canadians that plied the waters in birch-bark craft. Our canoe would be a 65-foot houseboat called the Chairman. On board was Steve Quinn, from In-Fisherman magazine, Mike Pehanich, senior writer for Bass Master, and Wes Remmer, from Cabela’s in Sidney, Neb.

Close to the lake, we began to see outcrops of ancient granite, some of the oldest rocks visible on the face of the planet. Here, at the heart of North America, it rises above the surface, an igneous structure that joins the Great Lakes to the Arctic and runs south into the United States. The Canadian Shield. Once, the ice here in northern Minnesota was two miles thick, and some of the surfaces still bear the ancient scars of the glaciers.

The fish too are prehistoric: pike, walleye, sauger and muskellunge with jagged teeth and powerful jaws.

We were armed with Cabela’s Platinum ZX spinning rods and Prodigy reels. Our guides, Billy Dougherty and Jon Balaski, had live minnows, leeches and nightcrawlers. Leaned into the corner of the boat were a couple of fly rods, a 6-weight for bass and an 8-weight in case we needed to tease a pike out of the cabbage. Ready for anything.

We started with a one-quarter ounce jig head and tipped the hook with a minnow. Here, the lake was 22 feet deep. Remmer dropped his bait in and lifted the rod when a walleye sucked the bait in.

I caught the next spiny rayed walleye, then Wes boated the next six.

With a boundary shared by Ontario and Minnesota, Rainy Lake covers 225,000 acres with 929 miles of shoreline. It is populated by 1,600 islands, which add another 635 miles of shoreline — big water, though rocky and shallow.

To learn the lake fast, we studied charts, watched the wind and prowled bays with the depthfinder to look for sunken islands and schools of baitfish. We started each day on the hunt for walleye then switched to smallmouth in the afternoon and ended by trolling for pike.

After lunch the first day, I threw a red and white popper with Cabela’s six-weight MTx fly rod. Against a rock cliff, I splashed the popper and when I chugged it, a fish broke water like someone had thrown a wheelbarrow in the lake.

I set the hook and stripped line as the fish blasted away then turned to charge the boat. That’s when I saw the bronze of its flanks, saw the popper pull from its mouth and the fish, a bigger bass than I have ever battled on a fly rod, turn straight away. To me, line slack, jaw slack, rod limp in hand, the bass looked as big as a Shetland pony.

We trolled huge baitfish imitations for pike. I chose a Storm Giant Flatstick No. 22 in a black and silver pattern. Jon ran the motor at 3.4 to 3.6 mph and zigged and zagged. In the next hour, four 26- to 30-inch northern pike smashed the bait.

On Rainy Lake, an angler can keep walleye smaller than 17 inches and no more than one over 28 inches. I expected small walleye, but in fact, these were big ones. I only caught a few in the 12-inch range and most ran to 23 inches.

Trolling for pike, when my rod bent with the weight of a fish, I brought a 25 1/2-incher to the net. The next time the rod slammed down, it was a 28-inch walleye with the 11-inch stickbait in its mouth. The sting of losing that big smallmouth was lessened.

That night, we deep-fried our walleye filets and relived the day’s bite on the deck of the houseboat.

Fishing boats cruised the channel in the gathering dusk, with Canada on the starboard side and the United States off the port bow. They call these the Boundary Waters, and the line that divides two nations was defined by the route the French Canadian voyageurs established in the fur trade.

Toward the end of that era, in the 1840s, some of our family headed south out of Ontario, through these waters to make homes on what was then the American frontier. It wasn’t too hard to picture the land and water the way they saw it, nor the kids with fishing poles that were my grandparents not so long ago.

White strokes of cirrus spanned the western sky like the first brush strokes on a master’s canvas, then shaded to lavender and rose, bright against the sky in the last light of day.