The Firehole, Gibbon, Madison and all associated tributaries are closed in the park due to low flows and warm water temperatures. All other rivers remain open and are offering great dry fly fishing right now. Make sure your fly box is stocked with a variety of Stonefly, Caddis, and Mayfly patterns. There are lots of opportunities to throw terrestrials like Grasshoppers, Beetles, and Ants as well.