Free Resource · Updated 2026
The St. Joe River flows through the St. Joe National Forest in the panhandle of northern Idaho. It holds wild westslope cutthroat and bull trout in clear, cold water. The river runs through a scenic forested canyon with good road access in its lower reaches. Caddis and Golden Stone hatches are the highlights of early summer.
St. Joe River Hatch Calendar — Quick Reference
The St. Joe begins high in the mountains near the Montana border and flows west through Shoshone County to Lake Coeur d'Alene. The upper river in the national forest is the best trout water with wild cutthroat averaging 9 to 14 inches. Bull trout are present in the upper reaches and are catch-and-release only.
The river is accessible from the St. Joe River Road that parallels much of the upper drainage. Forest road access opens up sections that receive little pressure. The fish are not educated and respond well to attractor patterns through the summer.
Caddis are the most reliable hatch on the St. Joe from May through August. Golden Stones appear in late May and June. Hopper fishing is productive in the meadow sections from late July through September. October Caddis fire in the fall and can bring the largest cutthroat to the surface. BWOs provide action on cloudy days throughout the season.
See the full Idaho Fly Hatch Chart for hatch timing across all of Idaho's top trout streams.
Check Conditions Near St. Joe RiverWhat to Fish
Caddis are the engine of dry fly fishing on the St. Joe River. Dense hatches fire in June in the evening and the cutthroat feed actively across the whole stream. An Elk Hair Caddis in size 14 or 16 is the standard choice. The fish here are not selective and will take a well-drifted dry without hesitation.
Recommended: #14-18 Elk Hair Caddis, X-Caddis
Golden Stoneflies emerge in late May on the St. Joe and the hatch continues into July on the higher sections. Fish a large Stimulator or a foam-bodied Golden Stonefly near the banks during the morning hours. The cutthroat hit the large fly hard and the action can be fast when the hatch is on.
Recommended: #8-12 Stimulator, Golden Stonefly
October Caddis on the St. Joe River are a highlight of the fall season. The big orange caddisflies appear in September and draw the largest cutthroat to the surface. Fish an orange Stimulator in the afternoon near the banks and in the tailouts of pools. Fall fishing on the St. Joe is often uncrowded and the October Caddis hatch is one of the best reasons to go.
Recommended: #8-10 October Caddis, Stimulator
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