South Fork Gamble

(Fishing In Idaho, by Arthur Shilstone)

While the first two management strategies seem scientifically sound, they depend on abundant resources to be effective. Some studies show that low flows in winter followed by high flows in spring improve spawning success for cutthroats, while relatively high winter flows and low spring runoffs favor rainbows. The research suggests that the spring flush needs to be 15 times the average winter flow to achieve the desired results. But water is precarious in the West. During years of acutely high or low snowpack, there either isn’t enough water to flush the river or there’s so much that flushing would overfill the next dam downstream. Realistically, this approach works one out of three years.

Cutthroats also prefer particular tributaries for spawning. Idaho began building weirs and fish traps on primary spawning creeks in the mid 1990s as part of its cutthroat survival plan. Every day between March and June, a fisheries technician removes all the fish from the traps, placing the cutthroats upstream of the weir and transporting the rainbows to urban ponds around Idaho. Though the costs are offset with help from the Bureau of Reclamation, they remain significant. Shifting anglers’ attitudes appears the most sustainable hope for cutthroats on the South Fork.

In 2004, Idaho drastically changed the regulations. Keeping a cutthroat is now illegal, but it’s open season on rainbows and hybrids. Fish and Game concurrently started a campaign to educate anglers about the benefits of killing the right fish. The problem is that catch and release is gospel to many anglers, who continue their habit of popping hooks and letting blushed flanks slip subsurface.

In 2009, Idaho Fish and Game instituted the “Angler Incentive Program.” IDFG catches 600 to 700 rainbows every winter (3 to 5 percent of the estimated total population) and hides coded wire tags in their snouts. The hope is that those tags will metamorphose trout into Powerball tickets. Fish with a tag in their head are winners, worth anywhere from $50 to $1,000 to those who turn in the heads.

That big rainbow I broke off might have been a jackpot. Older fish have been in the river longer and stand a better chance of getting tagged.

“There’s a big cutty in here,” he said, as we stared at the current. “Right there, on the shadow line.”

Judging by my two days at South Fork Lodge, the fishery remains exceptional. The guides knew the river well. Mayflies emerged each day around lunchtime, and I caught more trout on parachutes and small nymphs than I could bother to count. I even dug up a big brown on a streamer.

On the last afternoon, we floated the canyon section beneath towering stone rosettes. The guide anchored us in a deep pool that swirled against a cliff. Dozens of dark shapes waved in the slow current, occasionally tipping up to eat tiny bugs.

“There’s a big cutty in here,” he said, as we stared at the current. “Right there, on the shadow line.”

It took me a few tries to get the distance and a few more to figure out the currents. By then the fish had moved, and I had to recalibrate. Eventually I made a good cast, and we tensed as the fly approached the fish’s lie. A foot before it met the target, a much darker shape rocketed up and inhaled my parachute. A rainbow, lean but angry, came to the net.

“What should I do with it?” I asked.

“Up to you.”

“What would you do?”

“I’d let it go.”

The rainbow didn’t look menacing. It looked wide-eyed and fragile and more than a little annoyed, like all the other rainbows I catch and delicately release each year. Without thinking too hard, I popped the hook and returned the fish to its pool—not because I’m squeamish. I’ve just never been comfortable stopping heartbeats for ideals.

Anglers appear wary about using rainbows as betting chips, much as they were wary of catch and release a generation ago. None of the guides admitted to killing fish or encouraging their clients to do so. But recent river surveys suggest that cutthroat populations have increased as rainbow numbers have dipped.

The programs seem to be working. However, as Regional Fisheries Manager Dan Garren explained, they aren’t a solution; they’re a stopgap. Without indefinite management, cutthroats will be outcompeted here as they have been throughout the West. Idaho is hoping to reverse that trend by rekindling the acquisitive impulse in anglers with a nod to Las Vegas, a pretty successful place. I’m more angler than gambler, more annoyed than intrigued by flashing lights and ringing bells. But if you happen to love gambling as well as fishing, and don’t mind killing rainbows, I suggest a week at South Fork Lodge. Penn and Teller won’t be performing any magic tricks, but the scenery will be much better. 


Miles Nolte is a product of the catch-and-release generation. For better and worse.