The Firehole is beginning to warm enough that the revival chances of C&R fish diminish each day. Fishing on the Madison depends mostly on quality of the PMD emergence. Because of the removal actions last year, the Gibbon above Virginia Cascade is essentially fishless. Meadow sections on the Gibbon below, however, are offering evening brown drake emergences. A more sporadic brown drake emergence is ongoing on Duck Creek.
Northeast side streams (Slough, Soda Butte, Buffalo Fork, and Pebble Creeks and Lamar River) are beginning to drop and therefore need more time to offer good fishing. Trout Lake is “mossing up” making dropper and surface fishing the only ways to go.
Fall River streams are under going erratic flows because of weather and snow remaining on Madison and Pitchstone Plateaus above. This is mosquito season in the basin (and at many other park locations), so dress accordingly. Beula Lake offers very good fishing especially for those willing to carry a flotation device into the lake. Speckled dun and damselfly activity there means life cycle patterns will work. So will small leech and bead head nymph patterns. The same applies on a smaller scale to Riddle Lake with a shorter walk (about a mile) off the South Entrance Highway
Streams of the upper Gardner River drainage, such as Glen, Indian, and Obsidian Creeks, etc. are now great places to take entry level fly-fishers. Small but aggressive brook trout make up the fishing here, and the best action is away from the roads.
The Upper Yellowstone River (above the Falls) opens July 15th. Below Grand Canyon the river is discolored from Lamar River inflow, but offers some success for those presenting streamer, woolly bugger, and rubber leg patterns.