Two numbers out of Lewiston
The Lewiston gauge sits a short walk below the dam and reads almost exactly what the Bureau of Reclamation lets out. Under the Trinity River Restoration Program that is usually one of two numbers: a 450 cfs summer base flow, kept high enough to hold spring Chinook temperatures, and a 300 cfs winter base flow that starts around October 15 and runs until the spring releases. The range on this page is those two figures. Fly Fishing Specialties wrote in February 2026 that flows were "finally back to 300cfs out of Lewiston" and fishing hard, and The Fly Shop's September 22, 2026 report had releases dropping to 450 with steelhead of 23 to 27 inches in the catch.
Anything well above 450 means a restoration release is running. The 2000 Record of Decision raised the river's share of Trinity inflow from about 25 percent to 48 percent, and the program shapes that water into spring pulses. 2026 was classed a Dry year with 453,000 acre-feet: releases peaked at 4,300 cfs on April 24, receded to 750 cfs by June 9, bumped to 1,450 on June 15 and were back at 450 by July 3. Winter storm pulses of up to 6,500 cfs are allowed between December 15 and February 15 when the forecast at the gauge above the North Fork reaches 4,500. The Fly Shop notes the upper 40 miles, dam to North Fork, clear within a day or two of a storm because so much of the water is released, not rain.
The fly-only water under the dam
From 250 feet below Lewiston Dam down to the Old Lewiston Bridge, CDFW allows only artificial flies with barbless hooks, and the reach is open April 1 through September 15. The Trinity River Hatchery sits at the top of it, off Trinity Dam Boulevard on Hatchery Road, with an underwater viewing window worth ten minutes on a slow afternoon. The Trinity Fly Shop, on Lewiston Road since 1982, guides this water and Lewiston Lake above the dam.
The Fly Shop describes the summer fishing here as smolts of 8 to 14 inches and half-pounders of 16 to 20 once the restoration water is gone in July. Give the upper river room in winter. The Fly Fishing Specialties guide who swings from Cedar Flat to Douglas City wrote that he stays off the stretch from Steel Bridge up to the dam so spawning steelhead can finish.
Douglas City to Cedar Flat, the swing water
Below Lewiston the river runs past Steel Bridge, Douglas City and Junction City along Highway 299, and drift boats float as far as Pigeon Point. The Fly Shop lays the season out this way: summer-run fish from July, the bulk arriving in September, building through October and peaking in November, most of them hatchery fish; then winter fish from about Thanksgiving, mostly wild and getting larger as the season goes. The restoration program's own life history has summer steelhead entering from May 1 to October 30 and winter fish from November 1 to April 30. Half-pounders, fish that spent only two to four months at sea, show in late summer and fall; the program lists the Rogue, Klamath-Trinity, Mad and Eel as the only rivers that have them.
Swinging works through the whole season. Black and blue was the color in the February report, with golden stones swung on the same tips. The Fly Shop guides nymph from November through February, with Pat's Rubberlegs in 4 to 8, Psycho Prince in 12 to 16 and an egg pattern behind them once the salmon are on redds.
Salmon quotas, clipped fins and Cedar Flat
Everything below Lewiston Dam falls under the Klamath River Basin section of CDFW's 2026 regulations. Only barbless hooks, and only steelhead or trout with a healed adipose clip may be kept, two a day; wild steelhead and all coho go back. From the Old Lewiston Bridge down to the Highway 299 West bridge at Cedar Flat you may also keep 10 brown trout. For 2026 the Fish and Game Commission reopened Chinook after three closed years: a spring-run season from July 1 through August 31 above the South Fork, and a fall-run season from September 1 through December 31 with a 536-fish quota for Lewiston to Cedar Flat and another 536 for Hawkins Bar to the Klamath. The daily limit is 2 Chinook with no more than one over 23 inches until a quota fills, then jacks only.
The piece people miss is Cedar Flat to the Denny Road bridge at Hawkins Bar, which is closed to all fishing from September 1 through December 31. The lower Klamath quota filled on September 13, 2026, but CDFW said the Trinity stayed open. Quota status changes weekly; the Klamath-Trinity hotline is 1-800-564-6479.
Willow Creek, Hoopa and Weitchpec
Below Hawkins Bar the river leaves the Highway 299 canyon at Willow Creek and turns north into the Hoopa Valley. The Hoopa Valley Tribe issues a River Access Permit that, per its own form, puts an angler in compliance with Tribal Code section 15.3 and authorizes access at named sites; it asks for your California license number, and cars parked without a tribal parking permit can be towed. Get the permit before you park.
This fall the river also has a new fixture. On September 8, 2026 the tribe and CDFW dedicated a joint counting weir near Tish Tang Campground, replacing the Willow Creek weir CDFW had run since 1978, and state rules close the water within 750 feet of any department counting weir. Downstream of Hoopa the Trinity meets the Klamath at Weitchpec, where the Klamath section rules take over.