Firehole River

The Firehole River is one of the most unique trout streams in the world, flowing through the geyser basins of Yellowstone National Park where boiling hot springs and erupting geysers line its banks. The geothermal influence gives the Firehole a character unlike any other trout river: its waters are warmed by thermal inputs, creating conditions that produce prolific insect hatches and active trout feeding earlier in the spring and later into fall than the park's other streams. The river holds brown, rainbow, and brook trout that have adapted to this extraordinary environment, feeding in clear, meadow-stream water while steam rises from the surrounding thermal features.

The Firehole's most celebrated stretch runs through the Biscuit Basin and Midway Geyser Basin areas, where the river meanders through broad, grassy meadows with undercut banks that shelter surprisingly large trout. The fishing here is technical and intimate, demanding careful approaches, delicate presentations, and small flies that match the river's prolific hatches of blue-winged olives, pale morning duns, and caddis. The Firehole is exclusively a wade-fishing river with easy access from the park road, and its relatively gentle gradient makes wading comfortable in most sections. Summer can be challenging because geothermal warming pushes water temperatures above the trout's comfort zone, effectively closing the river to ethical fishing from late June through mid-September. However, the spring and fall windows provide some of the most atmospheric and rewarding dry fly fishing available anywhere, with the sight of a trout rising to a mayfly while Old Faithful erupts in the background creating an experience that exists nowhere else on Earth.