Madison River, especially Firehole River below Old Faithful, and Gibbon River below Norris are warm enough not to be recommended for good fly-fishing success. Soda Butte Creek, the lowest two meadows on Slough Creek, and Lamar River in roadside meadows are very crowded. There is fast fishing for small brook trout in the upper Gardner River drainage especially away from easy access points. Diminishing green drake activity, PMD’s and evening caddis activity offer some action on the Yellowstone River above the upper falls. Number of cutts are down, but size is up. Streamers are best bet to encounter the larger cutts there. Fall River Basin streams are running a bit high but clear and therefore fishing well. Hoppers and other terrestrial insect patterns are best bets for action. Trico activity should start any time. Beula Lake offers some of the fastest fishing in the park. Shoreline can get a bit crowded from time to time due to boy scout visits from nearby Camp Loll, so pack in a float tube and get out in the lake to fish back towards shorelines with speckled dun, damselfly, and cinnamon caddis life cycle and small leech patterns.
