Chris Clarke writes about steelhead. It’s a subject I’m on close terms with, too; my father was an obsessive steelhead fisherman, and I grew up spending many memorable weekend mornings chilled and damp on the banks of the Green River, eyes fixed on the tip of a fiberglas rod. I also felt the year-by-year decline, as actually catching a magnificent fish became a rarer event over time. I was interested in the biology of these fish, though, and these are also things my father explained to me: