Warm River

Warm River in Idaho is a smaller, spring-fed tributary of the Henrys Fork of the Snake River, located near the town of Ashton. Its name comes from its relatively constant and moderate water temperature year-round, thanks to its spring origins. The origin of this beautiful, small stream is primarily attributed to Warm River Spring, a significant natural spring located in the southern part of the Yellowstone Caldera's flank. This spring emerges at a relatively constant temperature, giving the river its name and contributing to its stable flow throughout the year. 

The river is stocked with hatchery Rainbow Trout near the campground at lower Warm River. Hiking upstream from the campground or climbing into its deep canyon will be rewarded with wild Rainbow, Brown and Brook Trout. 

The consistent water temperatures help maintain insect hatches throughout much of the year, offering opportunities for dry fly fishing. It's a stream that rewards careful approaches and attention to the prevalent insect life.  Warm River is a perfect destination for those who appreciate a classic small stream fishing experience in a beautiful Idaho setting.