The Owyhee is the surprise package of eastern Oregon — a small, unassuming tailwater winding through high-desert ranchland below Owyhee Dam near Adrian, and it grows brown trout out of all proportion to its size. This is big-fish water dressed up as a meadow creek: cold, nutrient-rich releases out of the bottom of the reservoir feed a thick population of wild browns, with rainbows mixed in, and a hatch calendar that punches well above its weight — pale morning duns and blue-winged olives, a famous crane fly show, midges through the cold months, and trico and caddis in their season. Because it's a tailwater the game is reading the release, not the sky: a stable, moderate flow is the sweet spot, and the irrigation season can shove the river up and color it. The catch is the catch's namesake — the dam draws off a reservoir that can warm, so the summer water isn't always the reliably cold flow you'd hope for, and the river can run off-color and warm when it's worked hard. Fish it for the browns it's known for, watch the flow and the clarity, and treat the trophies with the respect a small river's big fish deserve.

• Volcanic

• Aquatic life: Impaired
• Fish consumption: Impaired
• Recreation: Impaired