Caddisflies stay active on most of our small streams this time of the season. Terrestrial insects also become important food forms for trout. As discussed in our Yellowstone Park report, having patterns for these along is now important. The other consideration to realize is that many of our smaller streams are warming up as waters drop to base levels. Streams that have a large water component from springs (Birch, Big Elk, Bitch, Diamond, Little Lost, Teton River) or water from lakes with subterranean outlets(Palisades) tend to stay cooler longer than those that do not have as much of such (Robinson, Bear, Pine, Upper Blackfoot) or are subject to draw-down ( lower Fall River). So concentrate your efforts on those with cooler inflows and be sure to have terrestrial patterns in your fly box.