Hybridization with non-native rainbow trout is a huge problem for native cutthroat trout. Both rainbow and cutthroat trout spawn in the springtime, making hybridization a common occurrence in certain waters. The species are closely enough related that the hybrids are viable, but these “cutt-bows” dilute the genetic stock of the native species. Non-native trout also compete with cutthroats for habitat and food, further threatening the existence of our native fish.

In most large Rocky Mountain rivers, introduced rainbow, brown, and brook trout have totally displaced the native cutthroat trout. Dams have complicated the issue in many systems by blocking access to the tributaries where cutthroat prefer to spawn.

The South Fork of the Snake River is an anomaly. This tremendous tailwater hosts native Yellowstone cutthroat trout, including some really big ones. Over the last five years, TU has been working with Idaho Fish and Game (ID F&G) and numerous other conservation organizations to help this population of sensitive native fish.

While Yellowstone cutts have persevered in the South Fork, their successes must not be taken for granted. Damage to spawning tributaries, low winter flows from Palisades Dam, development in the valley, and hybridization with rainbow trout are very real threats to these fish.

Matt Woodard is spearheading TU’s Home River Initiative on the South Fork. Like all of TU’s “Home River” projects, this one takes a comprehensive approach to coldwater conservation.

I spent a day with Matt and I tired out my fingers while taking notes on all the great conservation work in the valley.

To reduce hybridization with rainbow trout, TU and ID F&G have been advocating that anglers keep rainbows and cutt-bows from the river. The state changed the creel limit so that an angler can keep as many rainbow trout as they’d like.

No one has any illusions about removing rainbows from the system entirely, but angler harvest has proved to be an effective way to help keep the non-native fish population in check.

At first, anglers and guides were reluctant to harvest the rainbow trout, Matt told me, but the initiative has become quite successful. While rainbows will always be known for the aerial acrobatics that follow a hookset, let me tell you, I have fished all over Yellowstone Country and the cutthroat in the South Fork are the strongest I’ve ever hooked.

Besides their broad shoulders, anglers have embraced these fish for their willingness to suck down dry flies and the rich colors on their flanks.

Most importantly, catching a native trout is enjoyable in and of itself. It is nice to know that the fish belongs in the river and that its ancestors have eaten stoneflies here for thousands of years.

The heart of the South Fork River Initiative lies in the restoration of the stream’s tributaries. Cutthroat trout prefer to spawn in tributaries, even the really small feeder streams. Some of the tribs to the South Fork have been disconnected from the main river for irrigation purposes.

A big part of Matt’s job is working with landowners to gain permission to restore the natural stream channels on their land. Most of the landowners in the valley want to do what they can to help the fish, but it’s Matt’s job to assure them that TU will work with them as a constructive partner.

Fortunately for all, Matt is great at this aspect of the job and the trout are truly benefiting from these partnerships.

Matt showed me Garden Creek and Rainey Creek, two of the channel reconnection projects. Work has included replacing culverts under the highway to allow fish passage, updating irrigation systems to increase water use efficiency, and screening the diversion inputs to prevent fish from entering irrigation ditches. In addition, a key irrigator has promised not to divert water from Garden Creek until after July 1st, leaving more water in the stream during the cutthroat spawn.

These projects depend on support and funding from many groups and agencies including the US Fish and Wildlife Service, Natural Resources Conservation Service, and the One Fly competition.

Local volunteers from the Upper Snake River TU chapter have also been actively involved in tributary restoration. Matt Woodard was chapter president before taking his post as a TU employee.

Early results are promising. This last spring, only weeks after the reconnection was complete, a mature cutthroat was observed in Garden Creek.

The adult cutthroat trout are the attraction for the thousands of anglers who visit this river each season. Matt floated me down an upper stretch of the river in his driftboat, a big aluminum steelheading boat that worked great in the South Fork’s powerful flow.

We threw hoppers, yellow sallies (small yellow stoneflies), and general attractor dry flies to likely lies. The weather was scorching hot and we didn’t have one of those epic South Fork days where every fish in the river is looking up, but we stuck a few trout.

I hooked one large cutthroat. We watched it slowly and deliberately rise to my hopper imitation and suck it down. If I close my eyes, I can still re-play this "picture perfect" rise in my head. Well, the fish went upstream while the current carried the boat towards the ocean and the hook pulled out. Still, it was nice to see such a fine native trout.

I got a little taste of the river and saw its potential. I can’t wait to get back and fish the South Fork again. Likewise, visiting the first stages of the South Fork improvement efforts was inspiring. I look forward to following the progress of this impressive conservation effort for decades. This project is the real deal.

I encourage you to visit the South Fork for yourself. Catch beautiful native cutthroat trout on dry flies and enjoy a rainbow cooked over the campfire.

Visit the photo gallery HERE

Click HERE to read more about the SF Snake Home River Initiative