Snake River
Water temperatures have decreased with cooling weather. Claassenia has been about and is most prevalent from Moose down to Sheep Gulch. While caddis are around in the morning hours and there are a few yellow sallies from time-to-time, PMDs dominate the surface action – although not is big numbers – from around noon until 4pm or so. Side channels, troughs, and riffle pools have offered the best surface production. Eddies are another option worth considering. Parachute Adams, Parachute Extended Body PMDs, DL Cripples, and Film Critics are solid choices for PMD imitations at the moment. Fish them in tandem or with a Stimulator to imitate a yellow sallie.
Streamer fishing has been productive and remains so below South Park but is now more hit-or-miss from Pacific Creek until well downstream of Wilson. Moderately sized patterns are working best when fished on floating lines, sinking tips in the INT to 3ips range, or short lengths of T-8. Target currents with moderate speeds along banks and structure, in troughs, and on the current margin of seams. Definitely vary up your retrieves and allow your rigging to sink every now and then.
South Fork
Flows from Palisades Reservoir stand at just over 9,000cfs. PMDs are still emerging in decent numbers in the afternoon and should be your main focus during that time period if targeting riffles, flats, eddies, and seam current margins. While there are some caddis bouncing around in the morning hours, there are also mutant stones starting to appear for the first time this year on the South Fork. This makes early morning hours a good time to be skittering foam attractors along the surface. Focus primarily on banks, structure, troughs, and side channels. Surface action on these patterns can continue well into the afternoon, partly due to the fact that grasshoppers have been out in good numbers. As such, a Parachute Hopper or Dave’s Hopper can be a good choice when focusing on the surface.
Streamers have been working very well on all reaches with literally no section outperforming the other. Different tactics will be required depending on which reach to fish. The upper section in Swan Valley and the lower below Byington is fishing best with sinking tips in the INT to 3ips range and slow to moderate retrieves. The canyon sections are fishing best with floating line, a heavily weighted pattern/s, and moderate retrieves bordering on fast line strips. Larger patterns are producing best in the canyon while moderately sized baitfish imitations are working best on the upper and lower reaches. No matter your section of water, target banks, structure, parallel drop-offs, and eddies and seam current margins. Posting up on flats and swinging a pattern downstream can also produce.
Salt River
As has been the case since runoff subsided, the Salt is fishing well with good action in eddies, seams, riffles, and troughs. This is despite a slowdown in hatch activity except for tricos ,which are dominating everything else combined. Dry-dropper rigs are outperforming tandem dry setups. Keep your dropper tippet in the 14” to 30” range. The most productive nymphs include perdigons, Egan’s Iron Lotus, and Lightening Bugs.
Flat Creek
Emergences are squeezed into tight windows with sporadic caddis early (between 6:30am and 8:30am) and late (7pm until dusk) and PMDs popping intermittently between 11am and 1:30pm. Craneflies continue to be worth focusing with subsurface larva imitations working along structure and undercut banks. PMD surface patterns are working well – albeit for an hour or so maximum on seams and riffles. Tricos can be the dominant hatch some days, and when they are out expect to see them from around 10am until 2pm. Grasshoppers are around in good number and there can be a little bit of opportunistic feeding in deeper water along banks and in eddies, although you will get better action on a dropper nymph. Water temps have cooled some, although it it still worthwhile to end your fishing early – say by or before 2pm.