|Lower Mesa Falls, Henrys Fork, Targhee National Forest.|
The Henrys Fork drainage provides one of the most important rainbow trout fisheries in the state in terms of habitat, fish populations, and angler use. Important tributaries include the Teton, Fall, Warm, and Buffalo rivers. Henrys Lake and Island Park Reservoir are important components of the Henrys Fork fishery.
The Henrys Fork Snake River below St. Anthony suffers from impacts of irrigation withdrawals and low flows which limit salmonid populations.
The Henrys Fork from Riverside Campground to Island Park Reservoir supports a world famous wild rainbow trout fishery.
Island Park Reservoir is a widely fluctuating irrigation reservoir with a mean surface area of 8,400 acres. It provides an important reservoir fishery for rainbow trout and kokanee. The fishery has been affected by loss of fish downstream through the dam and by other unknown factors since a 1992 renovation.
From Island Park Reservoir upstream to Henrys Lake, the Henrys Fork provides a yield fishery supported by natural production and supplemented by hatchery catchable rainbow trout.
Henrys Lake outlet is a low gradient stream section which flows through an intensively used, privately owned cattle grazing area.
Trout emigration from Henrys Lake supports the majority of angler harvest. Cutthroat spawning in the three miles below Henrys Lake Dam is very obvious.
Henrys Lake is a shallow, highly productive lake covering 6,500 acres in the headwaters of the Henrys Fork. It has a long history of supporting an extensive sport fishery for large, native cutthroat trout. Since 1924, hatchery operations at the lake have taken cutthroat eggs for use in maintaining cutthroat trout fisheries in many areas of the state, including Henrys Lake.
Warm River is a major tributary to Henrys Fork. Warm River base flow is provided by large springs six miles upstream from its confluence with the Henrys Fork. It has large sections of good spawning gravel and fairly constant temperatures which make it ideal for trout spawning. Rainbow and brown trout migrate from the Henrys Fork to spawn in Warm River during spring and fall, respectively.The Fall River is the largest Henrys Fork tributary. The Fall River supports an excellent wild rainbow trout fishery.