A Dry Fly Paradise

by: Shaun Lawson

The South Fork of the Snake, River is a tail water fishery that flows out of Palisades Reservoir and runs for 64 miles before its confluence with the Henry's Fork. The dam was constructed in the 1950's and the reservoir holds about 1,400,000 acre-feet of water. The stored water is used for agricultural irrigation and power generation. As a tail water, the river enjoys fairly constant water temperatures that promote a healthy fish and aquatic insect population. The river boasts a trout population of about 3,000 adult fish per river mile. Water flows range from as high as 22,000 c.f.s. in early June to about 2,000 c.f.s in October and November. The South Fork is the best cutthroat trout fishery in the country and from mid-August through mid-October it is often referred to as "the best dry fly river in the world".

The upper section of the river, from Palisades downstream to the Heise measuring cable, opens on Memorial Day Weekend and the season runs through the end of November. The river below the Heise measuring cable is open year round. On a normal snow-pack year the river runs high and slightly off color until about July 4th. Anglers who fish the river in the early season should exercise extreme caution as the flows often exceed 20,000 c.f.s. Fishing big nymphs and streamer patterns in tight to the bank can provide some decent fishing even when the river is high and off color.

The Salmonfly hatch marks the start of the dry fly season on the South Fork and can provide some of the most exciting fishing available. The hatch generally starts in late June in the Twin Bridges area and works its way up the river to Swan Valley by mid-July. Some of the best Salmonfly patterns are the Improved Sofa Pillow, Birds Stone, Henry's Fork Salmonfly, and Orange Turk's Tarantula all in sizes 4 to 8. Fishing weighted stonefly nymphs along the bank ahead and behind the hatch can also be very effective. The Super X, Black Rubberlegs, and Girdle Bugs are some of the most productive nymph patterns.

Yellow Sallies start to show up around the same time as the big Salmonflies. A Yellow Sally is a small golden stone in sizes 12 to 16 and in July the air can be filled with them. Yellow Stimulators, Lime Trudes, South Fork Sallies, and Mormon Girls seem to fish the best.

The Golden Stone also hatches at about the same time as the big Salmonflies and they continue to hatch intermittently all summer long. During August and September, when the water level is dropped, a mutant form of the Golden Stone hatches. As the water recedes the nymphs are stranded on the rocks, rather than die they hatch. Most of them have undeveloped wings and are sterile. They get on the water in pretty good numbers, and can be seen scurrying along the surface. The famous Chernobyl Ant was developed to imitate this form of the Golden Stone. Chernobyl Ants fish best when skated slowly along the bank and can produce some very violent rises. The best Chernobyl Ant pattern is one with a black back and a tan body in sizes 4 to 10.

The Pale Morning Duns usually start emerging around mid-July. On the South Fork, the PMD hatch is the biggest and most productive mayfly hatch. It lasts most of the summer and the fish can't resist them. The fish seem to move into the shallows to feed on the small bugs, so focus on the riffles and side channels. The PMDs start at about a size 14 in July, and have shrunk to a size 18 by late September. Our PMDs are a little different from those you may encounter on other rivers; they like to wear a pink suit. The Pink Cahill Parachute is the most popular pattern. I have found, personally, that the fish seem to take the regular color of PMD almost as well as the pink; but having some pink PMDs in your box may give you the slight edge that you need. The parachute pattern floats high and is easy to see in the riffles where the fish concentrate to feed on these insects. Late-July marks the arrival of the caddis and they usually last until mid-September. The most plentiful caddis have a speckled wing, a tan body and range in size from 14 to 18. The best caddis fishing is on calm, warm evenings. When the caddis are thick on the water, it seems every fish in the river is up. You have to see it to believe it. The best patterns are Elk Hair Caddis, Parachute Caddis, Brown Stimulators, and Hemingway Caddis. Try skating caddis patterns in the same fashion as a Chernobyl Ant, it can produce some effective results.

The South Fork has some amazing hopper fishing in August and September. Some of the most popular patterns are the Parachute Hopper, Dave's Hopper and the Henry's Fork Hopper. Tan seems to be the color of choice. There are always reports of fish being caught on hoppers all the way into the middle of October!

Nymph fishing is also an effective way to catch fish. Whenever the dry fly action is a little slow, try nymphing some of the riffles and side channels. Adding a nymph dropper to a big dry is an effective way to catch fish along the banks. Standard bead head patterns such as Pheasant Tails, Prince Nymphs, and Serendipities are generally the most popular.

The other significant mayfly hatch on the South Fork is the Mahogany Dun. They start to show around mid-August and go through mid-October. They are found mostly in sizes 16 and 18. Again, the parachute seems to be the best pattern. Try fishing a CDC emerger as a dropper to fool some of the more selective fish you might encounter. The fall streamer fishing can be very exciting. The South Fork has a high number of brown trout that become more active as the spawning season approaches. In act, the state record brown was caught in 1981 on the South Fork. It measured 36-1/2 inches and weighed a whopping 26 pounds! The fall holds the best opportunity to catch a trophy size fish. The best streamer patterns are Clouser Minnows, Double Bunnies, Zonkers and Woolly Buggers in all colors and sizes. Whenever the fishing is slow at any time of the summer these streamers can produce fish.

The fall dry fly fishing is mostly with Blue-winged Olives (BWO) and midges. The BWO hatch right up until the end of November, and the surface action stays pretty consistent. When the fall temperature is cool the best dry action is in the afternoon. The best patterns are BWO Parachute, Parachute Adams, Olive Humpy and Royal Wulff in sizes 18 to 20. If the fish are keying on midges, you can't go wrong with a size 20 Renegade or Griffith's Gnat.

The winter fishing on the South Fork (below the Heise measuring cable) can be terrific on days when the temperature goes above freezing. Early spring offers the best winter dry fly action on this stretch. From mid- March until the start of the runoff in mid-May there are some wonderful Baetis and Midge hatches. The South Fork of the Snake truly is a year round resource for the fly fisherman!