Rainbows rise again on the Henry's Fork - rainbow trout

Sunset, June, 1994 by Bruce Raskin

One of the West's classic fly-fishing streams stages a comeback

DUSK IS RAPIDLY fading to dark as I zigzag my way through the stubby sage and head upstream along the bank. In less than 20 minutes the trout will stop rising, but for now, massive ripples regularly break the river's even flow as several big trout gulp down insects floating on the surface.

I ease out into the river until water almost seeps over the top of my waders, strip 30 feet of line off my fly reel, and cast an imitation caddis fly slightly upstream of one of the fish. Three casts later, the water erupts beneath the fly, and line begins to shriek off the reel. Soon a hefty 19-inch rainbow comes to hand, and before dark I release two more good-size fish.

These were only a sampling of the big, muscular rainbows that fly-fishers landed last year on the 6-mile Railroad Ranch section of the Henry's Fork of the Snake River, in southeast Idaho.

Until the past season, the Henry's Fork--one of the West's premier trout streams--had been in serious decline for more than a decade. Gradual loss of habitat for juvenile trout, combined with six years of drought, had left both anglers and conservationists wondering if the river would ever return to its former glory.

Then in 1992, in an effort to deliver water for irrigation and to eradicate the trash fish in Island Park Reservoir (above Railroad Ranch), the U.S. Bureau of Reclamation (with the blessing of the Idaho Department of Fish and Game) drew reservoir levels down to record lows, sending more than 50,000 tons of sediment into the river. It's too soon to tell if that sediment will have a long-term impact on the fishery.

HOW THE TROUT GOT OUT

When the reservoir was drawn down, thousands of healthy, oversize rainbows from the reservoir went along for the ride. Based on a sample count, the fish population in Box Canyon alone (the 3-mile section below the reservoir) jumped from 3,000 in the spring of 1991 to 11,000 in the summer of 1993.

River-watchers consider the influx of fish a stroke of pure dumb luck, but there's no denying that last year the Henry's Fork fished better than it had in the previous 15 years. Anglers--many of them novice fly-fishers--typically caught 12 or more fish per day, several more than 20 inches, according to Mike Lawson, owner of Henry's Fork Anglers fly shop. Most experts are cautiously optimistic about the river's future, partly because of the catch-and-release, fly-fishing-only regulations.

Still, in spite of an outstanding 1993 season, anglers shouldn't assume that a successful outing on the river is a given. The Henry's Fork, a classic, smooth-flowing spring creek ideal for dry flies, is demanding water even for accomplished fly-fishers. The season runs from May 28 through November 30 (or June 15 through September 30 in the popular, easily waded Ranch section, from Stock Bridge to Osborne Bridge).

Anglers should expect insect hatches to vary dramatically from month to month, and even from day to day--with big, size 10 Green and Brown Drake mayflies in late June to tiny, size 20 cinnamon-colored flying ants in August.

Knowing which flies to use is only part of the challenge. "Fly presentation is most important--it has to be absolutely drag-free," says Nelson Ishiyama, owner of Henry's Fork Lodge. How to do it? "Move as close to the rising fish as possible without spooking them," he advises.

Being prepared for the hatches is essential. Local fly shops such as Henry's Fork Anglers (800/788-4479) will tell you which insects are hatching, right down to fly color and size. The shop also books guides for $275 per day (for two anglers). Fishing licenses cost $7 for a 1-day permit, $16 for 3 days, $31 for 10.

The Henry's Fork is about 27 miles southwest of West Yellowstone. The Railroad Ranch area has limited motel space, but try the Last Chance Outfitters (800/428-8338), a clean, no-frills operation. For more elegant lodging, there's Henry's Fork Lodge (208/558-7953 or 415/434-1657; reservations required), which caters to fly-fishers and has a gourmet restaurant, which is open to nonguests for dinner only. For breakfast, many anglers head to the Chalet (legendary for its scones with honey butter). The area is dotted with numerous campgrounds.

Other nearby attractions include Harriman State Park (hiking, horseback riding) and self-guided float trips on the Henry's Fork from Big Springs to Mack's Inn Resort (208/558-7272 for boat rentals).