Rainbow Trout

The Columbia River Rainbow Trout (Oncorhynchus mykiss) is one of the most sought-after game fish in North America.  Averaging 40-60 cm (16-24 inches), the rainbow is native to the Columbia River and prized by fly fishers for their hard fighting, line-screaming, high-jumping battles.

The Columbia River Redband rainbow (Oncorhynchus mykiss gairdneri) is a highly celebrated rainbow trout sub-species that’s believed to be a descendant of the anadromous steelhead trout.  Larger than a normal rainbow, Redbands average 24-28 inches in  size and are recognized by their deep crimson stripe from gill plate to tail.  While the species is endangered in other regions, this section of the Columbia River holds the largest populations of redband rainbow trout in the world.

The headwaters of the Columbia provide the pristine, well-oxygenated, cool water rainbow trout need to thrive.  It is estimated there are 1,000 wild rainbow per km on this last free-flowing section of river between the Arrow Lakes and US border.  Even with all these fish, on most days you won’t see another angler.

Rainbow trout are carnivores that live in cool, fresh water.  Rainbows that migrate into saltwater are identical, but are called steelhead trout. They generally feed on aquatic insects in the larval, pupal and adult forms as well as terrestrial insects and freshwater shrimp. The more food available the larger the fish will get.  Columbia River Rainbows are both plentiful and extremely well fed due to the amazing insect hatches, but even so, they are always ready to take a fly.

Depending on the season, local food sources may include stonefly, mayfly, dragonfly, caddisfly, damselfly, and terrestrials such as flying black ants, cicadas, grasshoppers, beetles, and other insects that fall into the water.  The caddisfly hatch in the summer months is nothing short of spectacular.  If you are on river you will see and hear the water erupt with rainbows in a feeding frenzy.

The most popular way to fish for rainbow is to imitate their food source while wet or dry fly fishing, but other productive methods include spin casting lures, fly and bobber, and bait.   Trout from 3-5 pounds are routinely caught, and monsters up to 23-pounds have been landed on the Columbia.

Rainbow trout fishing is good throughout the year, but the best fly fishing for rainbow is from April  to September.  In January and February, the big rainbows tend to feed on the bottom of the river, so a popular setup for bottom fishing is a 3-way swivel with weight, corky and bait.