With cooling weather and frosty nights terrestrials will become less important, but so far their populations are holding up. But look for streamer patterns to become more important as we get into fall fishing. Here’s why. Watch for Lewis River system browns to become active and begin moving towards outlets and inlets of Lewis and Shoshone lakes. Increasing numbers of Hebgen Lake bows and browns will begin going towards inlet streams. If you are a dry fly enthusiast, be sure to have BWO and October caddis patterns in your fly box, especially if you are heading to the Madison, Firehole or Gibbon.