Playing the odds in Idaho.
by Miles Nolte
FISHING IDAHO’S SOUTH FORK OF THE SNAKE RIVER in the fall is almost cliché. Riotous cottonwoods bleed the season into their leaves; elk trill, mayflies emerge, riffles drop into pools. The scenery in Swan Valley has nothing in common with Las Vegas. But if you’re a gambler, you might consider replacing that Sin City vacation with a trip to the South Fork.
Bring a light rod for dry flies and something bigger for streamers. Bring some luck, too. You won’t need it to catch fish—the river will take care of that—but you might win some cash and potentially help save cutthroat trout.
I drove down to the idyllic South Fork Lodge after work on a Friday, arriving in the dark. Dawn found me in a soft bed with a full view of the river. The morning was cold. Mist meandered between the deciduous murals lining each bank—a thinner, slower movement of water molecules hanging above the river itself. What I couldn’t see from my cozy repose under thick blankets were the species jockeying beneath that icy flow, or the management program intended to skew their odds.
As we eased the driftboat from trailer to eddy, the morning chill barely crept through my layers of wool, fleece, and down. I felt detached, like I was wandering through a Thomas Moran print. I thrust my hands into the river in search of clarity. All I found was cold. Rivers, like the fish they house, become abstractions only when we want something from them. Without us, they just flow, and the fish just swim, spawn, eat, die.
A couple of hours into the day, my streamer disappeared behind a red cheek. I set the hook hard. The fish swam parallel to us, not so much shaking its head as flexing its whole body. I was mesmerized: the water was so clear, the trout so close and brightly colored. When it made an upstream run I forgot to give line, and the leader popped. The guide and I exchanged grins.
“That was a nice ’bow. You might have got some money for that one.”
“Money? You guys sell fish to the restaurants in Jackson or something?”
“No man, from Fish and Game. You know, the bounty on rainbows.”
I was intrigued.
According to the state management plan, the South Fork of the Snake is home to “one of the few remaining healthy fluvial populations [of Yellowstone cutthroat trout] within their historical range in Idaho.” Neither rainbow nor brown trout are native to the Rockies. They were stocked here just as they were across the colonial world. The South Fork has long housed a harmonious abundance of cutthroat and browns. Though they can compete for resources, the South Fork offers plenty of food and habitat, and the two species respect each other’s privacy: browns are fall spawners; cutties procreate in the spring. Rainbows, on the other hand, pose a significant threat to cutthroats. The two species often hybridize, diluting the native populations and threatening their longevity.
After those years, rainbow populations exploded. By 2004, they made up 35 percent of the total catch, equivalent to cutthroats. That same year, Idaho launched an audacious plan.
Rainbows used to be scarce in the South Fork—in 1986 they accounted for 1 percent of total angler catch, despite their success in the adjacent main stem and Henry’s Fork. Traditionally, rainbows avoided the lower stretch of the South Fork, so it acted as a barrier, preventing them from getting well established in the upper reaches. That changed during the high-water years of 1996 and 1997, when abnormal precipitation caused 40,000 cubic feet of water to roar through Palisades Dam every second. That much flow can dramatically change rivers: gravel bars appear or disappear; banks erode; new channels appear and old ones dry up. After those years, rainbow populations exploded. By 2004, they made up 35 percent of the total catch, equivalent to cutthroats. That same year, Idaho launched an audacious plan.
Cutthroats on the South Fork are now protected by three distinct approaches: conserving primary spawning streams; timing spring dam releases to optimize cutthroat success; and turning rainbow trout heads into lottery tickets. (continued on page 2)