If you're walking through town, or driving, the canal is a constant inconvenience because you always have to go over a block this way or that in order to find a bridge to cross. When I lived on Pine Street, I had to cross the canal to get to the laundromat, the good restaurants, the happening bars, and my friends' houses. What's more, the canal can't even be thanked for providing all of the electricity for the city, because much of the wattage it generates gets fused into a power grid formed by a conglomerate of electricity production facilities downstate. And on top of that the 97-year-old canal carries on its currents a constant reminder that the Saint Marys River, which was once the unmolested travelway and fishery of the Chippewa Indians, is now a docile stretch of water stocked full of exotic pests, tapped by industries, and divided by dikes and canals like a giant rope unbraided into a tangle of weak threads.

One would think that the canal is a contemptible beast, unfit for a town as lovely as Sault Sainte Marie. But I must admit that my hatred for it is tainted by a deep love, for the canal is an inauspicious yet excellent place to catch native Great Lakes whitefish, one of the finest-tasting creatures in the world.

Figuring that we'd be getting up early, I gave Drost my number and headed for the door. Drost called after me. "The only thing is," he said, "I'm leaving now. I want to be sure to get the good spot."

"Now?" I said. "It's not even two in the morning."

"Well, not exactly now. But I'll pick you up in 15 minutes."

"Where are we gonna go?" I asked. "Ashmun Bay?"

"No, man, the power canal. Where it dumps out of the dam."

Reminding myself to act like the kind of person I want to be, I said, "Great. Let's go."

Sault Sainte Marie, a northern-tier border town surrounded by water, unproductive farmland, and national forests, is not on a typical nine-to-five office schedule. It has about 16,000 residents, and aside from the roughly 3,000 students from the university these are mostly teachers, loggers, miners, Forest Service workers, members of the Coast Guard and merchant marine, or prison guards from the nearby penitentiary. The only rush hour in town coincides with the closing of the bars; it starts at 1:30 a.m. and lasts until 2:30 a.m. College guys in Chevy S-10 pickups cruise laps up and down the strip, yelling at girls. Police drive slowly by. Boyfriends and girlfriends get in arguments next to cars, make up, and drive home. Then, suddenly, the busyness ends and the streets go empty. The town doesn't make any sound at all. It is my favorite time of night. It is an excellent time to think, and fishing is usually what I'll think about.

As I walked home to grab my rod and some warm clothes, I recalled a time I had tried to catch brown trout in the power canal, and the time I'd tried to catch whitefish on nearby Ashmun Bay. Truth is, I hadn't had the best of luck in either case. I'd fished the canal when my brother, Matthew, was visiting. We took our rods, climbed up on a big slab of concrete, and tried with all our might to land a cast in the middle of the canal, where fish were sucking up mayflies. We had a theory that these browns were the size of vacuum cleaners.

My brother back-cast so hard that he hit a slab of concrete behind him and broke his brand-new rod. Two kids watching us got into a fight. The bigger one trounced the little one and then rode off on the poor guy's bike. An older man pulled up in a truck to tell us that the water is poisoned and that we'd get sick from those fish. I told him that these fish came from Lake Superior, and that Lake Superior was one of the most pristine, healthy water systems in the world.

He drove away. We decided that it was impossible to reach the fish, and left.

I'd been even more unsuccessful on my first whitefish outing. My roommate, Danny, and I had decided to build a spearing shack, hoping to spend our deep-north winter huddled over a propane heater while swigging Boone's Farm wine and spearing fish. We nailed old sheets of plywood to a frame built out of disassembled oak shipping pallets.

We put our shanty on Ashmun Bay, which is on the Saint Marys River above the rapids between Lake Superior and Lake Huron. Several hundred yards from shore, I sawed a hole into the ice with a chainsaw. We positioned the shanty over the hole and tuned in Border Rock, WKLT, on a portable radio. Danny dumped two baggies of boiled macaroni and a jar of maggots, which we'd purchased at a local gas station (where you can usually find whatever leaf worms or night crawlers or maggots or leeches or spawn sacks you might need in the milk and soda coolers), down the hole for fish chum, and we watched the current carry them out of view before they could sink. Danny went outside, took an ax from the sled, chopped a small hole 20 feet upstream, and dumped more chum into that hole. Luckily, much of it settled on the riverbed below our shack.

We waited several hours. A large pike swam by, uninterested in chum. A school of menominee swam by and I tried to drop the spear on them but they moved out of its way. Several times I hallucinated Atlantic salmon beneath our hole. They are the Holy Grail of the northern Great Lakes, and I've always lusted to have an encounter with one, but Danny assured me that I wouldn't see any on this side of the Sault rapids.

Soon, one whitefish swam past too quickly for a clean shot. A few hours later another whitefish came through. He was about as long as from my elbow to the tips of my fingers. He lingered around picking up macaroni and then seemed to fall as close to asleep as a fish can get. Danny held the weighted spear directly over the fish's back and let it slip from his hand. The fish wiggled frantically on the spear's tines but quickly tired, and Danny pulled it up. I looked at it for a long time, then tossed it out into the snow next to all the yellow spots we had made by drinking Boone's and relieving ourselves. After another couple of hours it was too dark to see into the water, so we left the shanty—pretty much forgetting about it—and went home. Later we baked the fish with paprika and lemon, and the white flaky flesh was delicious.

Toward spring, it came to my attention that we'd be subject to a hefty fine if we didn't get our structure off Ashmun Bay before ice-out. Danny and I went out, and after two days of chopping and sawing, we got our structure torn down and burned it on the ice. With the death of the shanty, I figured that I would resist any future inclinations to go after whitefish.

We bought gas, coffee, and maggots at a gas station, drove under the footings of International Bridge, which crosses the Saint Marys River into Canada, took a bridge over the power canal, and turned to parallel the Sault Locks. We passed a bar that used to be called the Horny Toad; after it burned down it reopened as the Satisfied Frog. Then we crossed the power canal again where it curves in toward the Edison Sault dam and widens to a quarter-mile from bank to bank, the full width of the hydroelectric plant. The dam and the building sitting on top of it don't look so much like an electricity production facility as they do a medieval castle set upon an outlandish moat.

A skiff owned by the university's aquatics lab was moored at the west end of the dam. We piled our gear in the bow and headed across the downstream face of the dam, where the water runs out and mixes in with the river's flow on its way to Lake Huron.

Across the river were the lights of Sault Sainte Marie, Ontario, population 85,000. I've always been amused by the contrast between the two identically named cities that border this river. The U.S. side of the river feels like a northern outpost, inhabited by rural people of Nordic descent, while the Canadian side is a southern city of that nation, largely Italian and industrial. Each side has a tendency to regard the other with a dismissive shrug. Cruising those boundary waters in a boat with no running lights feels dramatically smugglerish.

Whitefish from the great lakes average about two or three pounds. Their colors vary a little with locality, but they have greenish backs and bluish-silver sides tinted with purple iridescence. This sounds like an interesting palette to paint a fish with, but the most remarkable thing about a whitefish is how utterly nondescript he looks. He has a small mouth that points down and forward. He has a forked tail. He resembles, in shape, other freshwater fishes like herring and smelt. The word that comes to mind when I see a few whitefish together is "Biblical." If I imagine someone turning five fish into enough to feed thousands, I imagine them to be whitefish.

Of the 37 discharge tunnels, two offer superb fishing for whitefish. Why or how this may be is a mystery, and as Drost explained it to me I thought he must be kidding. I looked at the length of the dam—all 1,340 feet—and couldn't believe that a ten-foot-wide stretch about a third of the way in from the west end could really be that different from any other.

Yet Drost was adamant enough in his beliefs that here we were at three in the morning, not to fish, but to hold his spot at that particular tunnel so that we'd have it to ourselves at dawn. This seemed extreme at first, but once we were tied up to the wall of the dam, it seemed like a great idea. When it started to drizzle, it seemed a tad extreme again. Then Drost started the motor, gunned it, and drove into the tunnel to get out of the rain, and the trip turned scary for a moment. If we weren't in the dam's bowels, we were definitely in its rectum. When I turned out my flashlight there was darkness. I could feel the turbines spinning only feet away. It was very warm. I dozed off.

When I woke, a faint light was breaking outside the tunnel. Two old men in a new Starcraft fishing boat pulled up to our tunnel, the most coveted spot along the dam. The man in front was standing, brandishing a grappling hook over his head, preparing to hook to the stone wall. He looked triumphant about getting the spot. Drost called out, "Hey there, fella, we're fishin' this one." Drost's voice nearly knocked the guy over, and he peered into the tunnel like the generators were talking to him. Without saying anything, the men motored over a few tunnels. We backed out, hooked ourselves to the dam, and let out ten feet of rope. The cathedrals and industries across the river were becoming visible. I could just make out the rolling mountains of the Canadian Shield.

I rigged my line with a few pieces of lead split shot, tied two feet of tippet to the leader, and tied to that a small white fly made from the fur on a snowshoe hare's rear foot. Drost recommended a maggot on the fly. I cast into the tunnel. Before the fly had sunk far enough to tighten the line, it was already out past the boat. This can hardly work, I thought. I added weight to my line and tried the cast again. I shot my hook five feet into the tunnel, the weight pulled the line tight, and it swung like a golf club in reverse. I followed the line with my rod tip about ten inches over the water. The progress of the fly halted beneath the boat; I set the hook with a jerk and was into a slab of concrete on the bottom of the run. I snapped the line off, re-rigged, and cast again.

Drost, who was stretched out in the back of the boat, lazily putting his rod together, told me to use less line, because sometimes the fish lay suspended a few feet down. I cranked up some line, threw into the tunnel, and the drift stopped before it left the tube. I lifted up. A fish was there. It dove deep and I gave it line. It shot out past the boat on the current, rose near the surface, and popped off the hook.

"A whitefish has a soft mouth," Drost observed. "You can't hog them around like that."

"Like what?" I said. "I was giving him line." Drost shrugged.

After a few more casts, I hooked a small one, played it gingerly, and brought it to the boat. Drost netted the fish, thumped its head over the gunwale, and handed it to me. I sat down to enjoy the sensation of having just caught my first whitefish. I looked at it until I became self-conscious about my infatuation with the fish, and then slipped it into the cooler. In a few seconds, I cracked the lid to have another look.

Drost made a few casts off the other side of the boat. He hooked something that went zinging along the wall of the dam, heading east, and then dove out toward Canada, raced back in, and jumped three times about 40 yards from the boat, turning almost complete somersaults in the air. It was the size of a fence post.

"Shit!" Drost yelled. "It's a damn Atlantic salmon. All right! Hell, yeah! Shit, he's gone!"

The salmon are trying to return to their home spawning area, which doesn't technically exist, because they were hatchery-bred inside the Lake Superior State University aquatics lab, which is in the hydroelectric plant. Under a grant, the space was given to the school, and the lab's director has been trying to introduce Atlantic salmon into the Great Lakes ecosystem. When salmon run rivers to spawn, they try to return to the place where they hatched. Atlantic salmon are so good at this that many actually return to the aquatics lab. But the fish are liable to show up anywhere around the dam, and that keeps the excitement level way up.

In order for a fishing spot to be great, it has to offer the angler the possibility of a freakish catch. Michigan is full of places like this. While fishing for northern pike through the ice in Muskegon Lake, you might just hook a sturgeon that weighs a hundred pounds. When surf-casting into Lake Michigan in November, the possibilities are endless: steelhead, coho, menominee, chinook, lake trout, almost anything can come along. At the power canal, it's Atlantic salmon.

I know a guy—he seems to be a credible, honest person—who says that he hooked an Atlantic in tunnel 14 that came out of the water in a cartwheeling jump and landed in his boat. He threw it back overboard.

I would throw mine back, too. They are one of those things that have a lot more enemies in the world than friends.

The whitefish kept hitting throughout the morning. Sometimes I'd be casting up into the tunnel, only to look down and see several fish just two feet below me. I hooked fish beneath the boat, behind the boat, and on each side of the boat. I caught a steelhead no longer than my foot, and a sculpin no longer than my finger.

Around noon, the current from the dam shut off. The whirring generators hushed. The swells and bubbles disappeared from the rapidly flowing water; it was like a glass of soda going flat in hyperspeed. "Closing time," Drost said. He explained that every Sunday the engineers in the powerhouse shut down the turbines.

That's right, I reminded myself. They can do that. The power canal is not to be confused with a river.