California Fly Fishing 5 min read

DIY Guide to Fly Fishing the Trinity River in California

Ken Sperry

Posted by Ken Sperry

March 15, 2020

Trinity River in California

If there is one species known for its fighting spirit, it’s the steelhead. Averaging in at six pounds, steelheads’ determination and tenacity are well-documented by thrill-seeking anglers. And where do steelhead like to congregate? The Trinity River. 

Of course, there’s more to the Trinity River than its impressive population of steelhead.

The river also boasts local rainbows and browns, sea-run browns, coho salmon, chinook salmon, and smallmouth bass.

While the River has had its fair share of problems with water levels and migrating fish, we are happy to report that restoration efforts have greatly improved Trinity’s waters. 

The Trinity River is a great fishing destination for any angler looking for a challenge. Be sure to read our guide so you know exactly how to outwit the one of the world’s toughest fish species.

About Trinity River

Fly Fishing in the Trinity River

The Trinity River is a 165 mile long tributary of the Klamath River. The River was originally known as the Hoopa or Hupa by the local Yurok tribe.

The River begins in the Scott Mountains in Trinity County, California. It flows south and enters Trinity Lake, a reservoir created by the Trinity Dam. It is fed by Coffee Creek. It then flows into the smaller Lewistown Dam.

The River then passes through Lewistown and Douglas City, before turning northwest and receiving the North Fork Trinity River near Helena. At Salyer, Trinity receives its principal tributary, the South Fork.

From there, the River turns sharply north and enters Humboldt County. It flows through the Hoopa Valley Reservation, passing the towns of Willow Creek and Hoopa, before joining the Klamath River at Weitchpec (located near Eureka, California).

Trinity River Map and Fishing Access Sites

map of fishing access spots on the Upper Trinity River in California

Get Directions to the Fishing Access Points shown above with the DIY Fly Fishing Map

The Trinity River is primarily a rain-fed river, with the highest flows occurring between December and April, and the lowest occurring between August and October. The river’s flow also doubles when it receives the South Fork.

In addition to attracting fly fishermen, the Trinity River’s beauty also draws other adventurers. Whitewater rafting and kayaking are popular activities, as well as recreational gold mining. The River has been part of the National Wild and Scenic River systems since 1981.

The river runs through heavily forested areas, so you will be treated to breath-taking views as you tackle its waters. While you are likely to see salmon, bass, and trout here, the best and most satisfying fishing experience comes from taking on the steelhead trout that make an annual migration up river.

Best Places to Fish Trinity River

As this River is so large, there are many locations to access the stream.

If you are hunting for steelhead, it’s best to stick to the upper part of the Trinity River. The 25-mile upper section from the Lewiston Dam downstream to Junction City, offers the best year-round fishing on the Trinity.

Below the dam is a fly fishing only section. As much of the river flows through private land, be sure to pay close attention to signage when you are visiting.Much of the river is accessible to wade fishermen. However, there are areas in which you will need a drift boat. See the map above for access point and boat ramps.

Stream Flow and Current Conditions

As a tailwater, the flows on the Trinity are regulated by the Lewiston Dam and are fairly consistent throughout the year. The river reach below the dam fishes best between 300 and 1,000 cfs.

Be sure to check the river conditions before heading out to fish though. The USGS stream gauge near Lewiston, California provides a good indication of current conditions.

The graph below shows the stream flow (discharge) for the past 7-days. If flows are considerably above or below historical norms (yellow triangles on the chart) then fishing conditions ma not be ideal.


  • Temperature: 49.28 ° F
  • Streamflow: 1910 ft³/s
  • Gage height: 15.69 ft
Temperature GraphStreamflow GraphGage height Graph

Best Time to Fish Trinity River

Trinity River is open year round to fly fishermen with the exception of the special regulation section below the Lewiston Dam. You can have luck fishing during any time of the year. However, you will want to carefully time your visit around which species of fish you want to catch.

The best time to catch steelhead is in the winter and fall months. You can still have success catching steelhead well into March. The best time to catch Chinook salmon, on the other hand, is in the warmer summer months.

Fly Box – What You’ll Need

The special regulation section of the Trinity fishes like any other northern California mountain stream. When this river reach opens on April 1, March browns and blue-winged olives will still be hatching. Golden stoneflies will also be getting active and start to crawl to shore to begin emerging.

Caddis are the major attraction throughout the summer, along with PMDs and Little Yellow Stones. The fall brings a decent October Caddis hatch.

Here is list of general fly pattern recommendations for the Trinity River:

  • Blue Winged Olive (#16-20)
  • Golden Stonefly (#8-12)
  • Midges (various) (#18-20)
  • Pale Morning Dun (#14-18)
  • Caddis (various) (#12-18)
  • October Caddis (#6-10)
  • Salmon Fly (#4-8)
  • Callibaetis (#12-16)

Gear Recommendations

A 9-foot 5-wt or 6-wt fly rod with floating line is perfect for fishing dry flies and nymphs for resident trout and steelhead on the Trinity River. A tapered 9-foot leader, with tippet size 3X to 5X to match the flies you are throwing, is pretty standard.

Portions of the river also lend itself to swinging flies with a two-handed rod if that’s your thing.

Trinity River Fishing Report

Area fly shops, guides and websites that can provide a Trinity River fly fishing report are listed below:

Fishing Regulations

The special regulation section of the Trinity River, extending 250 ft downstream from Lewiston Dam to the the Old Lewiston Bridge, is open April 1 through September 15. The main stem of the river downstream of the Old Lewiston Bridget to the Highway 299 West bridge at Cedar Flat is open year-round.

The state of California requires that all people who are 16 years of age and older have a valid fishing license. There are resident and non-resident sport fishing licenses available. You can purchase a one-year, 10-day, two-day, or one-day license. Some areas also require a permit. You can purchase the license and learn about the most current regulations through the California Department of Fish and Wildlife.

Trip Planning Tips

The nearest airport to Trinity River, California is Redding Municipal Airport in Redding, California, which is about 43 miles from your destination. The closest international airport would be Sacramento International Airport, which is about 188 miles from the Trinity River.

Lewiston Hotel is a cozy choice if you are looking for accommodations in the area. As one of California’s oldest hotels, Lewiston Hotel will transport you to a different era, the Gold Rush era, while still providing modern comforts.

Of course, not everybody, and certainly not all anglers, needs modern comforts. Mary Smith Campground offers tent space and close proximity to Lewiston Lake. You’ll be surrounded by towering trees and wildflowers, with all the privacy you could ask for.

If Trinity River isn’t the best steelhead River in California, it is pretty darn close. Start planning your fly fishing adventure today and prepare for a challenging and rewarding experience.

Looking for more places to fish? Check out our DIY Guide to Fly Fishing California

Feature image by Ken Lund