Snake River Angler Fly Fishing Report for March 11, 2012 by Boots Allen

Unseasonably warm and sunny weather has invaded the Snake River area and the result has been some of the best early spring fishing we have experienced since 2007. Much of this is due to the higher than normal flows on the South Fork of the Snake River and the Snake River in Wyoming, but the weather has certainly helped over the past week. Here is what we are experiencing on our local streams -

Snake River

Early morning has been defined by strong hatches of midges and good nymphing activity with midge pupa imitation in riffles and shallow seams and eddies. The best action has been on Day-2 Midge Pupa (size 18), Ice Cream Cone Midge Larva (size 18 to 20), Rojo Midge Pupa (size 18) and Zebra Midges (size 16 to 20).

Air temperatures have been in the high forties by early afternoon and this is bring water temperatures into the low 40s. These warm temperatures are sparking moderately strong hatches of blue-winged olives and little brown stoneflies. While going subsurface with nymphs is still producing, the action on the surface has been strong enough that one can fish all afternoon with dry flies and expect consistent productivity. Olive Parachute Adams (size 16 to 18), olive Parachute Extended Bodies (size 16), Booty's BWO Emergers (size 16), and BWO Comparaduns (size 16 to 18) are working well in riffles and flats. Moderately sized attractors - particularly Tara Xs (size 10 to 12), Wills' Winged Chernobyl (size 10 to 12) in red and gold, and Snake River Water Walkers (size 10 to 12) in salmon, gold, olive, and brown - are bring up cutthroats along shallow banks, confluences points, and at the tails of riffles and seams.

The best fishing on the Snake has without a doubt been on the middle and lower reaches running from Wilson Bridge down to Astoria.

South Fork

Flows on the South Fork have been steadily on the increase since the beginning of the month. We are now at 4600 cfs. This is a terrific early spring level for this river. Warm temperatures in Swan Valley and the lower reaches of the South Fork around Byington and Lorenzo have made March fishing on this South Fork some of the best in the Rocky Mountain region. Air temperatures have been in the mid to high 50s on some days. Blue-winged olives and little brown stoneflies are the most prevalent hatches, but we are also seeing micro-caddis and some Rhithrogenia duns and October caddis at certain times during the day.

Nymphing has been productive on all sections of the South Fork with Hickey's Auto Emerger (size 16 to 18), Lightening Bugs (size 14 to 18), Dorsey's Mercury Caddis (size 16), Sanchez's Biot Bug (size 14), Robins (size 14) and Copper Johns (size 14 to 16) in olive, black, and red being the most successful. These patterns are fishing well in riffles, moderate to deep seams, and re-circulating eddies. They are working particularly well when fished as a double rig with Pat's Rubber Leg (size 8 to 10), RP Muskrats (size 8), and 20-Inchers (size 8 to 10).

Surface action has also been good with BWO and small caddis imitations in riffles and seams. Quigley Cripples (size 14 to 16), Booty's BWO Emerger (size 16), Furimsky BDEs (size 14 to 18) in black or olive, Lawson's Diving Caddis (size 16), and CDC Caddis (size 16 to 18) have been solid producers are are bringing up some really nice cutthroats and brown trout in the 18 to 19 inch range.

Streamers are also working well throughout the day. Bright baitfish imitations like J.J. Specials (size 8), Zoo Cougars (size 4 to 6), Clouser Minnows (size 4) in brown-over-yellow, and yellow Sex Dungeons have been productive along banks and structure and in deep riffles and seams. We have been fishing these on intermediate and Type III tips with standard or variable retrieves and slow to moderate stripping speeds.

It is hard to pick a portion of the South Fork that is fishing best. We have been concentrating on the upper reach in Swan Valley and the lower reach from Kelly Island down to Lorenzo. However, there are solid reports coming in from the Canyon reach as well. No matter where you go on the South Fork, it is bound to be good.
Henry's Fork
The Henry's Fork has been a great winter fishery since regulations changed several years ago, and this season has not disappointed. Fishing on the Henry's Fork is open from Vernon Bridge downstream to the confluence with the South Fork and on the Box Canyon reach below Island Park Reservoir. The warm, sunny weather over the past week has made the Henry's Fork a joy to fish. Nymphing has been excellent with good action on Hickey's Auto Emerger (size 16 to 18), chartreuse Copper Johns (size 14 to 18), Super Men (size 16), and Rainbow Warriors (size 18). These patterns are hammering rainbows when fished along structure in the Box Canyon section and through long riffles and along banks below Vernon Bridge.

Surface action has also been good on the warmer days, even when the sun is at its brightest. This is particularly the case from Vernon Bridge down to Chester and from Chester down to St. Anthony. Look for rising rainbows in riffles and on the downstream portion of structure. Imitations of blue-winged olives and micro caddis are your best bet. BWO Comparaduns (size 16 to 18), olive Sparkle Comparaduns (size 16 to 18), Pheasant Tail Emergers (size 18), and Booty's BWO emerger are the most productive patterns currently. Keep in mind that midges will be active throughout the day. Larva, pupa, and adult Chironomid imitations can be fished throughout the day with consistent action.