Snake River
A recent cold spell has dropped flows on the Snake significantly, but very warm temps have returned and the Snake is back into runoff. There are still opportunities with larger foam and rubber legged stonefly patterns imitating skwala (which will soon run its course) as well as soft hackle jig nymphs and large streamers. Nonetheless, this will end soon and the primary action is on the tailwater reach between Jackson Lake Dam and Pacific Creek, flows from the Dam stand at 2,000cfs. Water temps are cool, so most hatches will be midges with the possibility of BWOs on cooler, wetter days.
Moderately sized streamers are producing in bits-and-pieces but are getting into decent size above Worm Hole and can get into very good size on the lower reach. Target slow eddies, submerged structure, and banks. Switch it up between bright and dark and between a floating line and sinking tips in the 3ips to 6ips range. It is key to retrieve slowly and, at time, pausing your line strips every now and then.
South Fork
Flows from Palisades Reservoir stands at 11,000cfs. Water temps remain cool but there is action on nymph rigs and streamers with the most consistent production occurring on the lower reaches from Byington down to Lorenzo (good visibility) and on the upper reaches from the dam down to Conant (moderate visibility).
Nymphs rigs are key on the upper reaches where egg, midge, and BWO patterns are working in riffles, seams, back channels, and current margins. Focus on the lower half of the water column and be prepared for some soft eats.
Streamers are the name of the game on the lower reaches, although nymph rigs are certainly worth using. Focus primarily on troughs and seams. Full sinking hover lines and sinking tips in the 3ips to 6ips range and retrieve slowly. Both large and moderately sized imitations are working equally well. Slow to moderate retrieves are producing best.
Henry’s Fork
Most caddis as is typically the case this time of year. Quite a bit of variability in terms of hatch intensity. Some days are strong, while other days are moderate, but you will see them each day and their imitations are worth fishing. Nymph rigs are worth fishing in the morning hours from around 8am until 11am, after which surface patterns kick into gear. Swinging caddis pupa patterns has been very effective from around 1pm until 4:30pm. No matter which tactic you employ, target riffles, seams, overhangs, banks and structure and eddies.
Streamers have been working best on the lower reaches below Ashton. Moderately sized patterns are producing when fished along banks, structure, and seams, particularly slow to moderate currents. Larger patterns are doing the trick in faster currents. Go with dark to neutral colors and fish these on floating lines or sinking tips in the INT to 3ips range and moderate retrieval speeds.
Green and New Fork Rivers
Flows at Warren Bridge stand at approximately 450cfs and rising slowly. Still low flows but turbidity is also low and fishing has been good if your focus is size. We are seeing some rainbows from Fontenelle making their spawning run up the New Fork. If fishing streamers, it is good to focus on structure primarily (especially root balls and root wades), but there is also respectable action in troughs and at the head of seams. Go with dark patterns primarily. Brighter patterns are less consistent but can get into fish on sunny days. The New Fork has been good with streamers more so than dries or nymphs. Skwala is not a bigtime bug on the Green, but they are out and giving fly fishers respectable action on moderately sized foam. Brachycenrus caddis are also about and dominate most days. The best surface action has been on undercut banks, the tail of deep riffles and foam lines, and the inside margins of eddies. BWOs are in the cards on wetter, cloudier days. If the latter is your game, consider tying on a lightly weighted BWO swimming nymph pattern and swinging it as a dropper with an adult lead. This is getting into fish in riffles with moderate depth and along banks with moderate depth.