Firehole River

The Firehole River is a truly unique and fascinating fishery, directly influenced by the park's abundant geothermal features. Fed by numerous hot springs and geysers, the Firehole boasts exceptionally warm water temperatures compared to other trout streams in the region. This warm water creates a distinct ecosystem and a somewhat unusual fishing experience. 

This small river is known for its prolific insect hatches, which occur earlier in the season and can be quite intense due to the warmer water accelerating insect life cycles. Anglers can encounter significant hatches of midges, mayflies (like Baetis and PMDs), and caddisflies, often starting in late spring and continuing through the summer. This abundance of food can lead to a surprisingly large number of trout, primarily Brown Trout and Rainbow Trout, that thrive in this nutrient-rich environment. 

However, the warm water also presents challenges. During the heat of the summer, water temperatures can become stressful for trout, and fishing is often best in the cooler mornings and evenings. The fish can also be somewhat lethargic during the warmest parts of the day. Furthermore, the river's proximity to thermal features means that water temperatures can fluctuate, and there can be areas with very localized warm spots that trout will avoid. 

The river's unique character and the chance to catch quality trout in a landscape dotted with geysers and hot springs make it a memorable fishing destination. However, anglers need to be mindful of the water temperatures, especially in the summer, and practice ethical angling to minimize stress on the fish.