In eastern Idaho, the Henrys Fork of the Snake River is arguably the most famous fly fishing river in the USA. It is known for huge wild rainbow trout and for its amazing hatches. Within its 150 miles, you will find plenty of dry fly fishing stream running through ranch lands with quality pocket water.
The upper section for fly fishing the Henrys Fork is typically defined as the headwaters at Henrys Lake past Big Springs and down to Island Park Reservoir. There are plenty of riffles, pools and long runs to explore.
The middle section, below Island Park Reservoir, is probably the most popular. It starts with the tailwater fishery below the reservoir, then the confluence with the Buffalo River where the Henrys Fork enter the Box Canyon for some easier fishing. After the canyon, the river runs through Last Chance and Harriman State Park heading down through Cardiac Canyon on the way to Upper and Lower Mesa Falls.
In the lower river section below the falls, the Henrys Fork passes through Ashton Reservoir on the way to the confluence with the main Snake River.
For fly fishing access to the Henrys Fork River, there are several state routes that parallel the river including SR20 and SR47. There are numerous marked river access points.
Overall, Henrys Fork is the 7th most popular fly fishing river of all 17 fly fishing spots in Idaho.