Mayflies
Gammarids
The Firehole is a strange, lovely meadow river that slides past geysers and hot springs inside Yellowstone NP, holding browns and rainbows in some of the oddest country a trout ever lived in. It's a spring and autumn river by necessity — all that geothermal water shoves summer temperatures too high to fish in good conscience, so you leave it alone in the heat. Park special regulations apply. Swing a soft-hackle through the geyser-basin flats in the cool months and let high summer belong to the river.
The Firehole is the strangest trout river in America, and possibly the most beautiful. It runs through the heart of Yellowstone's geyser country, and the hot water of the basins — Old Faithful, Midway, the Lower Geyser Basin — bleeds into it until the river is literally warmed by the earth. Steam drifts off the meadows; the bank may be a bubbling spring. The result is a smooth, clear, weed-rich meadow stream that fishes early and late in the season when other rivers run too cold, and shuts down in midsummer when the geyser heat pushes it too warm for the trout's comfort. The bed is volcanic sand and gravel over rhyolite. The browns and rainbows here are wild and well-educated. Wading is easy on firm footing — but mind the thermal ground at the edges, which is exactly as dangerous as it looks.
Wading: Scalding thermal ground at the banks
- Mixed
- Unconfined
- Pool riffle