Boote drove us out of town and pulled off onto a two-track that led bumpily uphill between forested ridges. He took a fork to the right and then another fork and finally parked. He asked if I would be discreet about our destination. Not a problem. First, I was lost. Second, I understood that discretion is necessary because most of the north-shore rivers are small and can't bear much pressure. Also, and most important, the steelhead we were after are an entirely self-sustaining population-a rarity in the Great Lakes. Most of the more than 100 rivers along the Canadian north shore support steelhead runs, as do hundreds of others in Minnesota, Wisconsin, and Michigan. But the populations in U.S. waters are supplemented with regular plantings, while the Ontario rivers have not been tinkered with since the first West Coast steelhead were released in 1883. Some biologists think that the steelhead of northern Lake Superior are among the most genetically pure in North America. We put on our waders and took up our rods and stepped onto a path through the woods-black spruce and balsam, their branches draped with goat's beards of moss. Twenty minutes later we stood above a tumbling whitewater river snaking through wide beds of gravel. The water was tea-colored, as are nearly all Superior tributaries, tinted dark with tannin. At the outside of every bend were heaps of gravel that could have been shoved there by bulldozers. Beside the main channel were gravel troughs suggestive of highways under construction, where the river had flowed in previous years. Everywhere were piles of woody debris, including entire uprooted trees that had washed down the valley during floods. Boote explained that clear-cutting in the headwaters had caused the flooding. "What once were 100-year floods now occur once or twice a year," he said.