Overlooked by Mount St. Helens, Swift Reservoir is the easternmost of three large lakes created by the damming of the Lewis River.
Swift Dam was built in 1958 to provide hydroelectric power for nearby communities.
The other two lakes, also named for their respective dams, are Lake Merwin and Yale Reservoir.
Of the three, Swift Reservoir is the largest and is the only one stocked with catchable rainbow trout. (The other two have kokanee but modest numbers of mostly wild trout, and Merwin also is fished for tiger muskies.)
Don’t be intimidated by Swift Reservoir’s size (nearly 4,600 acres) or the limited shore access.
Particularly by fall, trout are so plentiful and aggressive in the large lake that an angler out boating on the water should get plenty of bites. The quality of fish tends to be high as well.
Swift Reservoir is excellent habitat for trout. The Washington Department of Fish and Wildlife puts tens of thousands of catchable rainbow trout — some 45,000 planned for a recent season — into the water every spring, in April or May.
Because Swift Reservoir is a fairly sizable lake, it takes time for the trout population to diffuse throughout the lake after it is stocked.
Also, its size makes it a far better choice for boating, and bank anglers will have a tougher time finding fish here. Shore fishing is likely going to be better at nearby Swift Power Canal (see below).
Early on in the season, the fish are most readily found near Swift Dam and local streams. As summer progresses, the fish will spread out.
Fall offers an excellent time for fishing the reservoir. By then, trout will have been eating natural food for several months and enjoying prime habitat, leading to a higher quality of fish.
Boaters often turn to trolling techniques to net trout most efficiently in large waters like Swift Reservoir.
A variety of small spinners, spoons and similar lures work well for trout. Just check the trout aisle at your nearest sporting goods store and you’ll find some that work.
Many anglers also will troll with a baited hook or bait the hook of a lure such as a Wedding Ring.
Lures and bait can be trolled alone or behind an attractor like a flasher or gang trolls. You might need extra weight or a downrigger if the fish are running deep, especially later in the season.
Bait fishing and fly fishing are other options to catch trout, which will be closer to the surface and within easier reach during the early season, when presenting a fly or fishing with bait under a bobber can work well.
For more on this type of fishing, see our primer article Trout Fishing: Basic How-To Techniques and Tips.
A few cutthroat trout drop into the lake from tributary streams but are a fairly rare catch.
Anglers may also encounter bull trout at Swift Reservoir. Taking bull trout or Dolly Varden is prohibited, and if you reel one in, you must release it.
Coho Salmon Fishing
The Lewis River is a natural spawning ground for coho salmon.
When Merwin Dam was put in during the Great Depression, it cut off the upper river as salmon habitat. In 2005, the Washington Department of Fish and Wildlife reintroduced coho salmon into Swift Reservoir so they can swim up into the river to find historic spawning grounds.
Adult salmon may not be retained, but their offspring will often remain in the lake, grow to catchable size, and show up in your net, where they can be harvested if they are between 8 and 15 inches. Coho that size are counted as part of the trout limit as long
Many coho are caught incidentally by anglers chasing the more numerous rainbow trout.
Territorial fish, coho salmon tend to respond to lures that agitate the water, such as spinners and jigs. Contrary to popular belief, coho are not always selective about the color of lure. Worm halves make good bait for pan-sized salmon.
Steelhead may be encountered at Swift Reservoir, but they must be released if caught.
What to Know Before Fishing Swift Reservoir
There are several rules for fishing at Swift Reservoir.
First and foremost, fishing is seasonal. The season begins the Saturday before Memorial Day, and it ends Nov. 30.
Fishing between the Eagle Creek Bridge and markers about 3/8ths of a mile below it is prohibited after July 15. Selective gear rules are in place for the latter area, so bait and barbed hooks are prohibited.
The minimum size of rainbow trout or salmon that may be taken is 8 inches. Smaller fish must be released.
As mentioned, salmon over 15 inches must also be put back. There is a combined daily limit of 10 trout and salmon that may be taken.
Wild trout, such as bull and Dolly Varden trout, must be released unharmed if caught.
As always, anglers should check for updated regulations each season, and rules can change now and then.
Fishing in Swift Power Canal
This artificially created channel is part of the larger hydroelectric project on the Lewis River system, carrying water from below Swift Reservoir a few miles down into Yale Reservoir.
While the giant Swift Reservoir is a boater’s paradise for trout fishing, Swift Power Canal is a good seasonal bet for bank anglers who don’t mind essentially fishing in a manmade ditch. Fishing from floating devices is prohibited.
It’s a good fishing spot for kids and people with disabilities to get within easy reach of plenty of willing fish.
WDFW stocks a portion of the canal each year with some 5,000 or so hatchery rainbow trout, usually in a couple of batches during the spring, when fishing here is best.
Bait fishing is the usual game here for easy trout catching, whether you favor natural or artificial options.
Lures or flies also will catch trout, as long as you find space to cast safely.
The canal was destroyed in the early 2000s, but after it was rebuilt and reopened in 2005, the state resumed stocking.
Also, there’s a nice accessible fishing pier where Forest Road 90 (extension of Highway 503) crosses near the canal’s midpoint, in an area where it’s legal to fish and catches are best.
Where is Swift Reservoir and Power Canal?
State Highways 90 and 503 link Swift Reservoir to Woodland in the west. It’s about an hour’s drive from Woodland, passing Lake Merwin and Yale Lake along the way, but it’s pretty much a straight shot from town out to the reservoir and dam.
Take Highway 503 out of Woodland and continue to follow as it becomes Road 90. The highway hugs the north side of Swift Reservoir, which is where several boat launches are located.
Toward the eastern end of the reservoir, you’ll find Swift Forest Camp, which has two concrete boat ramps. It’s part of PacifiCorp’s recreational amenities in the Lewis River hydroelectric system. There is a fee to launch on weekends.
You’ll reach the Swift Power Canal a few minutes before the reservoir, using the same route.