Stream trout feed more selectively than many gamefish. Whatever big trout are feeding on, whether it's insect larvae or minnows, it's important to use a presentation that looks and moves like the real thing. Most of the major diet items can be imitated by a jig. Tiny 1/64-ounce jigs tipped with a plastic nymph imitate nymph-stage insects, while a larger 1/16-ounce jig with a 1-inch white curlytail grub imitates a larger pupae or small baitfish. Jigs can be worked slowly (bounced lightly across bottom) or swum through deeper waters of pools and runs. In summer, cast jigs along under-cut banks, around deeper wood, below cascades into plunge pools, and behind boulders in runs.