David called me at 8pm. “You ready for tomorrow? Early start, I'll meet you there - trailhead at 4:30.” It was 1966 and we were 14, old friends who were now attending schools in adjacent villages. Maintaining our trout relationship was easy. We would probably climb mountains to chase our beloved quarry, fortunately our 200 foot hike down to the creek that morning was only a brief 20 minutes.
Our favorite watershed, like many on these Northern slopes which drop 700 feet to the Great Lakes plain below, is home to native Rainbow or Redband Trout, Oncorhynchus mykiss. Previous names include Salmo gairdneri and Salmo irideus. Rainbow trout are members of the Pacific trout and salmon subgroup of the salmon family (Salmonidae) which also includes the redband trout, cutthroat trout and golden trout. They rank among the top five most sought game fish in North America.
Rainbow trout are typically olive-green dorsally with brassy to purple iridescence. Back and sides are marked with dark olive to black spots. Mid-side markings include a wide red, pink or purple band that may either be a continuous band or be broken into a blotched pattern. Lower sides transition from silvery to white with white underside. The dorsal, adipose and caudal fins are light olive to amber marked with dark colored spots. Lower fins are typically pale shades of amber, orange, red, purple or gray and the anal and pelvic fins are often white tipped.
Rainbows prefer cool, clear streams and lakes, but can survive in lakes or ponds on the prairie, as long as there is cool, oxygenated water in the depths. They prefer water from 55 to 60 F, but will tolerate temperatures up to 75 F. Wild rainbow trout (within their native range) typically spawn during the late winter and spring with peak spawning activity in March and April when water temperature are between 10 and 15°C. However, spawning may occur anytime of the year. Spawning is triggered by increasing day length, water flow and water temperature. Rainbows typically migrate upstream to spawning areas with males arriving first. They may live up to 11 years, but the usual life span is four to six years.
The female digs several redds for depositing the eggs. She turns on her side and beats her tail against the bottom, moving the gravel away to create a depression longer than her body and about half as deep. As the female digs, she is often accompanied by more than one male. The largest male is dominant and defends his territory by charging the smaller ones. The male and female lie side by side and release milt and eggs. Sometimes the other males also deposit milt in the redd.
First introduced here in in our local in the 1870s, there appears to have been several species raised in the Caledonia New York hatchery and planted in local streams. Wild-caught and hatchery reared strains of this species have been transplanted and introduced for food or sport in at least 45 countries and every continent except Antarctica. The small guys (there are several subspecies) that David and I enjoyed rarely reached much more than 6 to 8 inches in overall length. But these were the fish that we had learned to love, with their spectacular fights and frequent acrobatic jumps, and are still the species that I treasure.
Typical lifespan is four to six years in the wild. Rainbow trout are predators with a varied diet and will eat nearly anything they can capture. Starting with zooplankton when they’re young, they routinely feed on larval, pupal and adult forms of aquatic insects such as typically caddisflies, stoneflies, mayflies and diptera. They are also partial to fish eggs, crayfish and terrestrial insects such as ants, beetles, grasshoppers and crickets. As they grow larger, baitfish assume a more important part of their diet. Rainbow trout will forage far from their established territories when food is limited.
Bank structure, in-stream wood and boulders, and riparian vegetation provide protective refuge and
hiding cover for rainbow trout. Undercut banks, overhanging vegetation, turbulent or deep water,
submerged or semi-submerged wood, aquatic plant beds, root masses, and large rocks also contribute
to habitat diversity for rainbow trout. But they are not as dependent upon cover, preferring open runs where they tend to feed at the surface more frequently than the other trout and char species.
Stocking hatchery-raised rainbow trout is not without controversy. The introduction of rainbow trout into eastern streams and lakes has resulted in competition for food and habitat with native brook trout (brook charr) and Atlantic salmon. Propagation of hatchery rainbow trout in the western United States
has resulted in a loss of genetic variation in native rainbow trout as a result of the mixing of hatchery and native individuals during spawning. These issues have raised awareness for the need to carefully plan and monitor the release of hatchery-raised rainbow trout into watersheds supporting wild trout in order to protect native populations of rainbow trout, cutthroat trout and other native fishes.
Flies to consider: Griffith’s Gnat, Elk-hair Caddis, Parachute Adams, Blue Winged Olive emerger, GR Hare’s Ear, Stimulator, Hopper, Pheasant Tail Nymph, Brassie, Buzzer, Egg Fly, Killer Worm, San Juan Worm, Prince Nymph, Utah Killer Bug, Soft Hackle Kebari, Coachman, March Brown, Olive Matuka, Brown Woolly Bugger, Black Killer Bugger, White Killer Bugger, Tan Killer Bugger.