Yellowstone National Park Fishing Tips

SOUTH FORK

Imagine yourself standing in knee-deep water on a gravel bar and casting to one of more than 20 large trout which are consistently sipping the surface in the midst of a prolific Pale Morning Dun hatch. You’ve already landed more than 15 nice cutthroat trout and the day isn’t even half over. Does this sound ideal? It is. As a guide on the South Fork I have had clients turn to me astonished, set their rods down and say, "I’ve fished a lot of years on a lot of different waters, but I’ve never seen anything that comes close to this." My response? "You’re right. It just doesn’t get any better." Of course, not all days are this easy, but then there is the old adage, "That’s why we call it fishing, not catching." Read on and you will discover what makes this river so magnificent, when and how to fish it, and the best choice of equipment.

The South Fork boasts 7,000 fish per mile, which qualifies it as one of the most productive rivers in the country. The quality of fishing on the South Fork has dramatically improved since a slot limit was introduced. All fish between 8 and 16 inches must be released and you are only allowed to keep two fish. Before the slot limit, most of the fish caught were kept and as a result the quality of fishing declined.

With the slot limit in effect and the majority of anglers practicing catch-and-release, the river has maintained a healthy population of breeding fish. The river is primarily a cutthroat fishery, however, it is also possible to get into a fair number of browns and rainbows. When a huge brown or ‘bow’ takes your fly you will know. The takes can be explosive and the ensuing battle spectacular. The only other fish to take you into your backing this quickly usually lives in saltwater. The South Fork of the Snake is in southern Idaho only 45 minutes from Idaho Falls. The South Fork begins as it flows out of Palisades Dam, forming a tailwater fishery. There is very limited access for wade fishing so a float trip is essential. A drift boat allows access to many of the productive gravel bars and side channels (otherwise inaccessible on foot) where you can then wade and cast to rising fish.

The first 10 miles begin at the Palisades Dam and end at the Spring Creek Bridge access. This section is the most accessible and as a result, the most crowded. Despite the crowds, some of the larger fish tend to be picked up on this upper section of the river. I have been on the river with dozens of other boats and still had phenomenal fishing. The banks on the upper section are graced with exceptionally large cottonwood trees and outstanding views of the rugged Big Hole Mountains. The 26 mile stretch past Spring Creek Bridge is considered the "Canyon Section," which is divided into two others sections called the middle and lower. There are many National Forest campgrounds along the riverbanks. Time permitting, camping is an ideal way to enjoy all aspects of the river. If not, both sections make for exceptional one-day floats as well. The canyon is spectacular, with walls towering hundreds of feet straight up from the river and dotted with pine trees. Bald eagles are prevalent and many nest high above on tree tops along the canyon walls. On certain sections you can cast from the boat into small caves where the fish hold out of the main current. How deep the fly lands in the cave determines how likely you are to get a strike. The occasional moose can be seen along the banks or even swimming past the boat. One afternoon I rowed my boat into a lunch slot only to find a large bull moose had beat me to it! It is common for an experienced angler to boat 30 fish a day with the average fish ranging from 16 to 18 inches. The South Fork is also excellent for less experienced fly fishermen to sight fish for large cutthroat, since cutts are not always easily spooked. The big browns and large cutts like to eat small fish so spin fishermen can expect results by casting Rapalas close to the bank and around structure. However, when the hatches are on, the fly fisherman is at a great advantage.

The fishing season begins Memorial day weekend and continues through mid October. For optimal dry fly action the river is best fished from July through mid August. The first half of July is the height of the prolific salmon fly hatch, which brings just about all of the fish to the surface to gorge themselves on one of the largest dry flies. If the hatch is not in full swing and the fish are not on the surface, try the Super X. The Super X is an excellent early season fly; it will take fish when nothing else seems to turn them. The key to fishing this fly is getting in tight to the bank and allowing it to drift just inches below the surface. The takes are aggressive so be ready!

This incredible hatch also brings in the anglers so I suggest booking in advance to assure a guide. As the salmon fly hatch tapers off, the Pale Morning Duns (PMD’s) and Little Yellow Sally Stoneflies begin to emerge. As the water level drops the fish can be found stacked up in the riffles like cord wood. This is also prime time to explore some of the smaller side channels since a lot of fish will be found in the slower water sipping trapped mayflies from the surface. It’s possible to hook and land a dozen or more fish from one gravel bar. This is one reason why the South Fork has gained a reputation as one of the greatest.

By the first week of August the fish are a bit more reluctant to eagerly sip your presented fly. For the selective fish, I like to use Mike Lawson’s No Hackle in sizes 16 and 18. When the fish continue to deny the dries, emerger and cripple patterns are highly effective, especially "when the fish are feeding in the riffles and back channels," explains Doug Anderson of The Lodge at Palisades Creek. "Last summer the hottest fly had to be the Lawson’s Cripple." I have also found the biot pattern to be deadly when the fish are feeding in the surface film.

The warm summer days of August bring out one of the trout’s all-time favorite foods, the grasshopper. The trout will eagerly hold along the banks waiting for the unfortunate hopper to drop into its feeding lane. The Dave’s Hopper or variations work best. These fish are slow on the take and require great patience from the angler. Wait for the trout to come up and take the hopper with conviction, then set the hook. When the fish are onto the hoppers but becoming weary of all the hopper patterns, try twitching a Turck’s Tarantula. The twitching motion of those rubber legs can drive the fish nuts and the takes are impressive.

Hoppers, Turck’s Tarantula and the Double Humpy are also excellent flies to set up with a dropper. Add 18 inches of 4X or 5X tippet by tying to the bend of the hook. If there are some PMD’s on the surface, tie one on to match; the large high floating dry works well to spot the small drys and emergers.

If there is no apparent surface activity try a Pheasant Tail or Hare’s Ear bead head nymph. Beadheads are hot and should definitely be included in your nymph arsenal. Just remember, when the hopper goes down, set the hook! I’ve had more than one client turn to me after missing a fish and say, "I forgot about the dropper!" This goes for dry as well as wet fly droppers. Fishing two flies is highly effective and should not be overlooked. By September the hopper action begins to taper off; however, the PMD’s will continue through the month. The fish are more selective this late in the season since they have seen just about every mayfly pattern imaginable. I have found that sending the fly downstream to the feeding fish is the most effective presentation.

October is a season of extremes, the fishing can be the best but the weather can be the worst. For those willing to take the gamble and come in October the rewards can be tremendous. I would have to say it is my favorite time on the river. For one, the browns are beginning to move to their staging areas to spawn. If it’s big browns you’re after, this is the month to come. The Idaho state record brown was set at 26.6 pounds and was taken on the South Fork. Monster browns in the 15-pound class are taken every year. I have had clients land browns more than 20 inches on dries such as the Double Humpy. However, this time of the year, streamers such as the Double Bunny are most effective. The Double Bunny was the winner of the Jackson Hole One Fly Contest two years in a row as well as winning the highest points in the contest’s history. That should tell you something. A streamer of this size requires at least a 7 weight rod. To be successful, the angler must be experienced at throwing heavily weighted flies and sinking lines.

Another bonus of fishing the river in the fall is only having to share it with very few boats. The fall colors, Indian summer weather, having the river to yourself, and excellent fishing all add up to a wonderful time to fish the South Fork. This, of course, can just as quickly change to high winds and blowing snow. That’s the gamble you take in October. The rods I recommend are contingent on what is being fished. For small dries, a 9-foot graphite with 4 or 5 weight line is ideal. For hoppers, Turck’s Tarantula and other large dries I recommend using a 6 weight or a faster action 5 weight graphite III. When fishing in the fall for big browns the rod of choice would be a 7 or 8 weight. For dry fly fishing a 9-foot 5X leader is a good start and allows for adding a foot or so of 6X for the most selective fish. For streamers a 7 ft. 2X will suffice.

I suggest taking two or three days to fish the South Fork to allow ample time for drifting the different sections. No matter what time of the season you decide to go, be sure to reserve a good guide in advance and be prepared to fish one of the world’s finest trout rivers. You’ll have to fish it to believe it.