Trinity River California Hatch Chart
Northwestern California, flowing west from its headwaters in the Trinity Alps through the Klamath Mountains before joining the Klamath River near Hoopa. The Trinity River is California's most significant steelhead river south of the Oregon border - a dramatic canyon river with wild summer and winter steelhead, fall Chinook and coho salmon, and resident rainbow and brown trout throughout its upper reaches. The upper Trinity above Lewiston Dam provides excellent year-round wild trout fishing in a remote mountain setting, while the lower river below Lewiston is the steelhead and salmon destination that draws fly anglers from across the state. The Trinity offers a diversity of fly fishing opportunities unmatched by any other Northern California river.
Check current California Department of Fish and Wildlife regulations before you go. The Trinity River has complex and frequently updated regulations that vary significantly by section and species - steelhead and salmon regulations are subject to annual updates based on run assessments and may include closures, barbless hook requirements, and gear restrictions. The lower river below Lewiston Dam is managed under a federal water release program that affects flows throughout the year - monitor USGS gauge data before wading the lower river. A California fishing license and a steelhead report card are required for steelhead fishing. Verify current regulations for your target section and species before every trip.
Shop by type: dry flies, nymphs, Euro nymphs, hoppers and terrestrials, streamers.
The river
The Trinity divides naturally into two distinct fisheries separated by Lewiston Dam. The upper Trinity above the reservoir is a smaller, more intimate mountain river - clear, cold, and accessible along Highway 3 through the Trinity Alps foothills with good populations of wild rainbow and brown trout in a setting that feels more like a Pacific Northwest stream than a California river. The upper river is the trout destination - year-round fishing, manageable flows, and the kind of diverse dry-fly fishing that makes a Trinity Alps base camp worthwhile for the angler who wants trout between steelhead runs.
The lower Trinity below Lewiston Dam is the steelhead river that defines the Trinity's reputation. Cold, clear dam releases sustain the steelhead and salmon runs through the canyon sections below Lewiston and Weaverville, with classic steelhead water - long runs, gravel bars, and the kind of varied structure that rewards systematic swinging and nymphing through productive holding lies. The canyon setting is spectacular, particularly in the Burnt Ranch Gorge section where the river cuts through some of the most dramatic terrain in Northern California.
Summer steelhead are the Trinity's signature fish - wild half-pounders and larger fish that enter the river from June through September and provide some of the finest summer steelhead fly fishing in California. Winter steelhead follow from November through March. Fall Chinook and coho salmon are present from September through November and provide additional fly fishing opportunities in the lower canyon sections. The combination of species diversity and the upper river trout fishery makes the Trinity one of the most complete fly fishing destinations in the state.
The Weaverville and Lewiston area provides full services for the Trinity River angler - lodging, fly shops, and guide services that know the current river conditions and regulations intimately. First-time Trinity steelhead anglers are strongly encouraged to hire a guide for at least one day to learn the productive sections, the proper swing and nymph approach for Trinity conditions, and the etiquette of this popular but uncrowded-feeling river.
Year at a glance
| Month | Primary fishing | Also carry | Notes |
|---|---|---|---|
| Jan | Winter steelhead, trout | Nymphs, streamers | Peak winter steelhead |
| Feb | Winter steelhead, trout | Nymphs, streamers | Winter run continuing |
| Mar | Winter steelhead, trout | BWO, nymphs | Late winter run, BWO begin |
| Apr | Trout, caddis | BWO, small nymphs | Spring trout season opens up |
| May | Trout, caddis, stonefly | PMD, yellow sally | Golden stone hatch upper river |
| Jun | Summer steelhead, trout | Caddis, golden stone, hoppers | Summer steelhead entering |
| Jul | Summer steelhead, trout | Hoppers, caddis, dry flies | Half-pounders, hopper season |
| Aug | Summer steelhead, trout | Hoppers, caddis, low water flies | Low clear water, small patterns |
| Sep | Summer steelhead, fall salmon | Hoppers, BWO, streamers | Chinook and coho entering |
| Oct | Fall salmon, winter steelhead | BWO, streamers, nymphs | Peak fall salmon, steelhead building |
| Nov | Winter steelhead, salmon | Streamers, nymphs | Winter steelhead run begins |
| Dec | Winter steelhead | Streamers, nymphs | Winter run building |
January - February
Peak winter steelhead season on the lower Trinity. The canyon sections below Lewiston hold fresh winter fish through January and February - nymphing and swinging through the productive runs and tailouts in the classic steelhead manner. The upper river provides good trout fishing through winter for the angler who wants surface action between steelhead sessions - midges and BWO on overcast afternoons in the clearer upper sections. The Trinity in winter is cold and demanding but the combination of winter steelhead in the canyon and rising trout above Lewiston makes it a productive two-species destination.
- Winter steelhead - lower river below Lewiston. Nymphing and swinging through runs and tailouts. Check current regulations before fishing.
- Trout - upper river above Lewiston Reservoir. Midges 20-26 and BWO 18-22 on overcast afternoons.
- Streamers for large holds in the deeper canyon pools.
March - April
Late winter steelhead through March with the run tapering into April. The upper river comes alive in spring - BWO hatches build through March and caddis begin in April on the upper Trinity sections above the reservoir. The spring trout fishing on the upper Trinity with BWO hatches and minimal pressure is genuinely excellent and represents one of the most underrated dry-fly opportunities in Northern California. The lower river trout fishing improves through April as flows stabilize from the dam releases.
- Late winter steelhead through March - lower river. Nymphing and swinging.
- BWO - 16-20 on overcast afternoons on the upper river. Building through March and April.
- Caddis - 14-16 beginning April on the upper river sections.
- Small nymphs subsurface throughout - upper and lower river.
May - June
The golden stonefly hatch on the upper Trinity in May is one of Northern California's most underappreciated big-fly events - large wild rainbows and browns responding to golden stone adults and waking dry flies in the pocket water and faster runs of the upper canyon. Caddis throughout. Summer steelhead begin entering the lower river in June - half-pounders and larger fish moving up through the canyon sections on the first significant summer flows. The June Trinity with golden stones on the upper river and fresh summer steelhead in the lower canyon is the river at its most diverse.
- Golden stone - 6-10 on the upper river in May and June. One of the upper Trinity's finest dry-fly events.
- Caddis - 14-16 evenings throughout. Building through May and June.
- PMD - 16-18 on the upper river flatter sections through May and June.
- Yellow sally - 14-16 in the riffles.
- June: summer steelhead entering lower river. Swinging and nymphing the canyon runs.
July - August
Summer steelhead season peaks in July and August on the lower Trinity. Half-pounders - the Trinity's signature juvenile steelhead on their first ocean return - move through the canyon sections in good numbers and provide some of the most exciting light-tackle steelhead fishing in California. Low clear water in August demands smaller patterns and careful approach on the lower river. The upper Trinity in summer is excellent hopper and caddis fishing with minimal pressure - the combination of morning hoppers and evening caddis on the upper river with summer steelhead in the lower canyon makes a Trinity week one of California's finest multi-species fly fishing experiences.
- Summer steelhead - lower river. Half-pounders and larger fish. Swinging smaller patterns in low clear water. Check regulations.
- Hoppers - 8-12 on the upper river July through August along the canyon margins.
- Caddis - 14-16 evenings on the upper river. Reliable through summer.
- August low water: smaller flies and lighter tippet on the lower river for steelhead.
September - October
Fall is the Trinity's most complex and rewarding season. Summer steelhead continue through September. Fall Chinook salmon begin entering the lower river in September and coho follow through October - the salmon presence brings additional fly fishing opportunities and the spectacle of large fish moving through the canyon pools. BWO return on the upper river with the cooling temperatures. Winter steelhead begin building in October. The Trinity in fall with multiple species active simultaneously is one of California's great multi-species fly fishing seasons - plan for several days to experience the full range.
- Summer steelhead continuing through September - lower river canyon sections.
- Fall Chinook and coho - September through October. Lower river. Streamers and swung flies for active fish. Verify current salmon regulations.
- BWO - 16-20 on the upper river on overcast afternoons. Fall olive hatches returning.
- Hoppers through mid-September on the upper river.
- October: winter steelhead beginning - lower canyon runs and tailouts.
November - December
Winter steelhead season opens in earnest on the lower Trinity. November and December bring fresh chrome fish into the canyon sections as the fall rains raise flows and trigger the winter run. Nymphing and swinging through the productive lower canyon runs in the classic steelhead manner. The upper river remains fishable for trout through November with BWO and midges on overcast afternoons. The Trinity in November and December is the winter steelhead river of Northern California - demanding, beautiful, and productive for the angler who commits to the canyon.
- Winter steelhead - lower river. Fresh fish with the first fall rains. Nymphing and swinging. Check current regulations.
- BWO through mid-November on the upper river - 16-20 on overcast afternoons.
- Midges - 20-26 on the upper river through winter.
- Streamers for large holds in the deeper canyon pools.
A western dry and nymph assortment covers the upper river trout season - add golden stone patterns for May and June and hopper box for summer. Steelhead anglers should carry a full range of swinging and nymphing patterns sized for the Trinity's clear canyon water. The Trinity River is California's most complete fly fishing river - wild steelhead, salmon, and trout across twelve months in a dramatic canyon setting that rewards the angler who takes time to understand its rhythms and seasons.